Instant Pot Stuffed S’mores Cake

WARNING: This is my favorite dessert recipe to date and may become addicting to any who tries it. 

S’mores are the quintessential dessert of summer (or really any occasion). But if you think you need a campfire to make them in the most decadent way possible, think again.

Folks, I present to you the Stuffed S’mores Cake that you can either serve as one giant cake OR as four, individual lava-style cakes! And you can have it either ooey-gooey or slightly firm and chewy like a brownie/blondie/cookie bar.

The secret to making it the best is pressure baking it in your Instant Pot. This is going to ensure it’s as decadently moist and perfect as they come – re-inventing and taking the S’more to the next level – ensuring that the marshmallow AND chocolate are both fully melted.

Once you give this one a go, not only will it become one of your favorite desserts of all time, you’ll always be wanting, well, S’more!  

Here’s How I Made It! (scroll to the bottom for the fully-written recipe): 

Let’s start off with our dry ingredients. In a large mixing bowl, add in some graham cracker crumbs… 

 …all-purpose flour…

…and baking soda (not baking powder) and salt. 

Whisk together until fully combined and set aside. 

Now, we’ll focus on our wet ingredients. In a stand mixer (or in another large mixing bowl if using a hand mixer) add softened butter… 

…light brown sugar… 

…and white sugar. 

Add the paddle attachment if using a stand mixer (the beaters are find on a hand mixer)… 

…lower the head and blend until creamed. 

It should look like a creamy, sugary butter when done. 

Now crack in an egg… 

…and add in some vanilla extract… 

…and pure maple syrup. 

Mix again until combined. 

It will be very creamy and slightly wet at this point. 

Now add the dry ingredients to the mixing bowl… 

…and mix until fully combined. (NOTE:Be sure to start at the lowest speed as the dry ingredients will go all over the place otherwise. Once combined, work your way up to a slightly faster speed). 

When done, it’ll look like a thick dough-like batter. 

Save every last ounce as we’ll be using it all!Now, let’s assemble this masterpiece! 

TO MAKE ONE LARGE STUFFED CAKE:Grab a 7×3 springform pan (NOTE:you MUST use this specific time of pan to do it perfectly). 

Butter the bottom and sides of of the pan generously. 

Then, lay in a 7″ parchment round… 

…and butter the top of that too. 

Now take about 1/3 of the dough… 

…and create a substantial bottom layer. 

Then, take about another 1/3 of the dough and attach it to the bottom while lining the sides of the pan. This is super important to do because it will create an out layer of the cake to make sure everything is secure inside once we stuff it. 

Work your way around the pan as if you were Patrick Swayze and Demi Moore in Ghost shaping it like it were pottery. When done, the entire bottom and sides should be lined with the dough, leaving about 1/4-inch of room from the lip of the pan. 

You should still have enough dough left to create a  top layer when we seal it. But first, let’s stuff this puppy up! 

Take an XL Hershey bar (and I strongly suggest Hershey for this as it makes the best S’more)… 

…and break it up. Gently nestle the chocolate pieces in the dough. 

Now, let’s get fluffy! Grab a jar of Marshmallow Fluff… 

…and smooth it out over the chocolate. 

You can use the entire jar if you wish, but however much Fluff you wish to add is up to you. 

Top the Fluff with another XL Hershey bar. 

Lastly, top with the remaining dough, being sure to thin it out so it covers the chocolate and marshmallow and attaches to the dough lining the sides. 

When done, it should look like this! 

Cover with foil… 

…add water to the Instant Pot… 

…lay in the trivet… 

…and rest the pan on the trivet. Secure the lid and cook at high pressure. 

When done, carefully remove the pot… 

…and let rest and cool on the counter with the foil removed. 

Use a pairing knife to get in between the side of the pan and the edge of the cake to loosen it. Now, you have the choice of one of two things:1. You can serve it while it’s still very warm and soft. It will be ooey-gooey like a lava cake.2. You can let it fully cool for about 3-4 hours and it will be firmer and chewy like a brownie/blondie/cookie bar. 

When ready to serve, unlatch the springform pan…. 

…gently lift the pan over the cake (it should come off with no issues)… 

…and do you see the side? THIS is why we had to line the side of the pan with the dough. It keeps everything in tact and inside the cake! 

Cut a slice… 

…pull it out… 

…and place on a plate. Clearly I went the route of Option 1 and served it in it’s warm ooey-gooey, messy, yet irresistibly decadent state. Look at that spectacular piece of heaven! Add some ice cream and serve it up!But wait. Do you want it as individual cakes instead? 

TO MAKE IT AS INDIVIDUAL LAVA-STYLE CAKES:Grab four 6-ounce glass custard ramekins… 

…and butter them all up from the bottoms to the sides. 

Distribute the dough evenly and line the bottom and sides of each ramekin with a substantial layer of the dough… 

…so it looks just like this. 

Then, layer in some of pieces of Hershey bar… 

…top with some Fluff… 

…and top with more pieces of Hershey bar. 

Seal it with more dough, attaching it to the sides of the dough lining the ramekin. 

When done, each ramekin should look like this! 

Cover each ramekin with foil. 

Add the water, trivet and rest three ramekins on the trivet… 

…placing the fourth on top of the three so it’s supported in the center. Secure the lid and cook at high pressure. 

When done, carefully remove the ramekins and place on the counter… 

…and remove the foil. 

Dig in immediately and collectively lose your mind as what you’re about to experience. 

Even better? Add a scoop of vanilla ice cream… 

…and because we’re already on the subject chocolate syrup.  

Whether you made it as lava cakes or one large stuffed cake, show that baby off! 

Now, the moment of truth. Give it a try. 

It’s going to taste you good you’re actually going to look mad for a second. Mad that you waited so long to do this. 

And then the madness will turn into disbelief at the miracle you’ve just made. 

…and then you’ll sport jazz-hands scoring out a perfect TEN because that’s exactly what this dessert is. 

The Stuffed S’mores Cake is exactly what dessert-time is all about!

Instant Pot Stuffed S'mores Cake (or S'mores Lava Cakes)
Yield: 6

Instant Pot Stuffed S'mores Cake

Instant Pot Stuffed S'mores Cake

When I released this dessert, everyone went absolutely bonkers. Picture everything you love about a S'more and then stuffing it into a cake so it becomes a huge lava cake of ooey-gooey chocolate and marshmallow engulfed in a dense and moist graham cracker crust.

Prep Time 5 minutes
Cook Time 1 hour 25 minutes
Total Time 1 hour 30 minutes


The Dry Ingredients:

  • 1 cup graham cracker crumbs
  • 1 cup all-purpose flour
  • 1/4 teaspoon baking soda (NOT baking powder)
  • 1/4 teaspoon salt

The Wet Ingredients:

  • 1 stick (8 tablespoons) salted butter, softened (either leave it out on the counter for 2 hours or so or zap in microwave for 10-15 seconds), plus more for greasing the pan
  • 1/2 cup light brown sugar, tightly packed
  • 1/4 cup white sugar
  • 1 large egg
  • 1 1/2 teaspoons vanilla extract
  • 1 tablespoon pure maple syrup

The Filling:

  • 2 XL-sized Hershey bars (about 4.4 ounces each. It MUST be a Hershey bar for the best S’more experience!)
  • 7 1/2-ounce jar Marshmallow Fluff


  1. Add the Dry Ingredients to a large mixing bowl and whisk together until fully combined. Set aside.
  2. Now let’s focus on the Wet Ingredients. In a stand mixer with the paddle attachment (or another large mixing bowl if using an electric hand mixer), add the softened butter, brown and white sugars. Start on a low speed and work your way to a 4-speed or medium speed until the butter and sugar are creamed, about 30 seconds. Add the egg, vanilla and syrup. Mix for about 15 seconds until combined.
  3. Add the Dry Ingredients and start on a low speed (flour likes to go all over the place so always start on a low speed) and once the dry and wet ingredients are combined, up to one speed higher and let mix for about 30 seconds until a thick dough-like batter has formed. Set aside.
  4. Assembling The Cakes:
  5. For One Large Stuffed Cake: Take a 7×3 springform pan and generously grease the bottom and sides of the pan with additional butter. Lay in a 7″ parchment round and butter the top of that too. Take about 1/3 of the dough and press it into the bottom of the pan, giving it a supple bottom of about 1/2-inch thick so it’s not too thin. Then, take another 1/3 of the dough and line it along the sides of the pan, attaching it to the dough on the bottom of the pan. It should come up to about about 1/4-inch below the lip of the pan. Like using a pottery wheel, work your way around the pan to make sure the dough is evenly distributed (check out the video for additional visual guidance). This ensures we’ll have outer edges of the cake and will keep the S’mores filling secure inside. Layer in one of the Hershey bars (break it up to lay it in properly or see the step-by-step photos for visual guidance) and then use a silicone or rubber spatula to smooth the Marshmallow Fluff on top (you can use up to the whole jar if you desire) and then top off with the remaining Hershey bar. Use the remaining 1/3 or so of the dough and lay it over the top Hershey bar layer so it’s totally covered and connected to the dough that came up to just below the lip of the pan. The top layer of dough should come up to just slightly under the the lip of the pan. Cover the top with foil, making sure you don’t press the foil directly onto the top layer of dough, but rather have it somewhat loosely on the pan.
  6. For Four Individual Lava Cakes: Take four 6-ounce glass custard ramekins (yes, it must be this size) and generously grease the bottom and sides of the pan with additional butter. Evenly distribute the dough, leaving some leftover for the top, and press it into the bottom and sides of each ramekin. Then, in each ramekin, add in about 2 pieces of the Hershey bar, followed by about 1/4 cup of Marshmallow Fluff, and top with about about 3-4 pieces of the Hershey bar. Distribute the remaining dough evenly to serve as a final layer on top of the Hershey bar and attaching to the dough on the sides of the ramekin. The top layer of dough should come be flush with the lip of the ramekin. Cover the tops of each ramekin with foil, making sure you don’t press the foil directly onto the top layer of dough, but rather have it somewhat loosely on top.
  7. Pressure Baking The Cakes:
  8. Add the trivet and 2 cups water to the Instant Pot.
  9. If making one large stuffed cake, rest the springform pan on the trivet, secure the lid, move the valve to the sealing position and hit Manual or Pressure Cook at High Pressure for 40 minutes. Quick release when done. Using the trivet’s handles with oven mitts or a dish towel, carefully transport the cake to the counter, remove the foil and let rest for 15 minutes to slightly cool. Take a pairing knife and get in between the perimeter of the edge of the pan and edge of the cake and loosen it up. Unlatch the pan and let the cake rest.
  10. If making four lava cakes, rest three of the ramekins on the trivet with the fourth resting on top of the center of the three. Secure the lid, move the valve to the sealing position and hit Manual or Pressure Cook at High Pressure for 25 minutes. Quick release when done. Using oven mitts or a dish towel, carefully transport the ramekins to the counter.
  11. Serving The Cakes:
  12. If you made the large cake, you can either serve it immediately, where the center will be super ooey and gooey like a giant lava cake OR let it fully cool for 3-4 hours and it will become like a S’mores Cookie/Brownie Bar! Slice into wedges when serving. Store any leftovers in an airtight container up to 3 days.
  13. If you made the four lava cakes, serve immediately as they SHOUL be ooey and gooey. To make it extra indulgent, add a scoop of ice cream (I used vanilla) with some chocolate syrup on top!

Jeffrey's Tips

As mentioned, if making the large cake, you have the choice of eating it while it’s still warm and ooey gooey OR let it fully cool on the counter for 3-4 hours until it’s firmed up and it will be just like a S’mores Cookie/Brownie Bar! OR you can have some right when its warm and save the rest for later in an air-tight container so it becomes like a cookie bar. You can also always re-heat in the microwave. Just DON’T put any leftovers in the fridge. We don’t want it getting THAT firm.

Always be mindful of how much dough you’re using as we want to make sure we have enough to properly assemble the cake(s). If you find you have too little dough left when sealing the top of the cake, just really thin out the remaining dough by patting between your hands. It’s far more important the bottom and sides has more than the top as it need to support all the filling.

Ice cream goes wonderfully with this if serving warm!

The important products I suggest for this recipe are:

Reader Interactions


  1. Marisa

    I can’t wait to try this! I was wondering if I could use mini marshmallows instead of marshmallow cream? Thanks!

    • Jen

      I wonder if weather/altitude is an issue. Tried making it on a hot and humid day here in Alabama, and I got a sticky, messy dough that was VERY hard to work with. I ended up having to add a lot more flour. It was still delicious, but a note has been made to try this again once the weather cools.

  2. Maggie

    I made this yesterday, only a vegan version and it was AMAZING! I used plant-based butter and a flax egg instead of animal-based products, I used a bag of allergy-friendly chocolate chips instead of Hershey’s bars and I used a bag of large vegan marshmallows instead of fluff (because I couldn’t find vegan fluff!). I followed the instructions word-for-word but I “baked” it for 50 minutes instead of 40. I was so nervous it wouldn’t turn out, but it did! I was so excited, but then we cut into it and the taste was so good and familiar! Everything melted, too! We ate half the cake warm and saved the other half to eat today. Great recipe, I’m so thankful things like this exist for people like me who don’t have an oven but still wants cakes and pies!

  3. Cat Kinney

    Could I make the dough ahead then bring my pan and ingredients to my son’s house to finish? My daughter in law has an upcoming birthday and it’s a s’mores fanatic so I would love to finish at their house so it will be gooey. She is the one who got me into the I.P. so I know she has one 😁

  4. Dawn

    This was good, but WAYYYYY too sweet. It’s literally melted Hershey bars and marshmallow fluff in a graham cracker pie crust. It’s hard to eat a small amount when hot, but would be easier when cooled.

  5. Nancy

    OMG is all I have to say! It was WONDERFUL! I just made another… with reeses peanut butter cups and mini marshmsllows!!! I’ll update or comment again after its taste tested!!!

  6. C.S.

    Just wondering how to store leftovers, as you mentioned to not store in the fridge. How long can they safely remain at room temperature? I’ve been wanting to try it for a while so may make it for Valentine’s Day!!

  7. Alanna

    Ok so I’m sure it will still be delicious, but my marshmallow fluff burst through the top of my crust! Any advice for next time?

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