S’mores Casserole Recipe: Indoor Campfire Dessert

You know what’s crazy? I spent years thinking s’mores could only happen around a campfire.

Wrong.

So wrong.

I finally figured out how to capture all that gooey, chocolatey, marshmallow magic indoors. No smoke in your eyes. No burnt fingers. No fighting over who gets the perfect golden marshmallow.

Just pure dessert heaven that comes together in your kitchen.

Here’s Why This Thing Works So Well

Look, I tried making indoor s’mores a bunch of ways before landing on this.

The secret? Layers.

We’re building a cookie dough base that’s loaded with crushed graham crackers. Already smelling good, right? Then comes the middle layer—Hershey’s chocolate pieces and mini marshmallows that melt into this ridiculous filling. Finally, more cookie dough goes on top with graham crackers pressed into it for crunch.

The texture is something else.

Every single bite gives you that authentic s’mores experience. Sweet marshmallow stretching between your fork and the plate. Rich chocolate melting on your tongue. And that unmistakable graham cracker flavor tying it all together.

Way better than regular brownies or cookie bars because of how everything layers and melts together.

Let’s Talk Ingredients

Each thing you put in this casserole has a job to do. Here’s the breakdown:

Ingredient	Amount	Why It Matters
Butter (melted)	11 tbsp	Makes everything rich and tender—use unsalted
White sugar	1/3 cup	Gets you those crispy edges everyone fights over
Brown sugar	1/2 cup	Keeps the inside moist and chewy
Vanilla extract	2 tsp	Brings all the flavors together
Whole egg	1 large	Holds everything together
Egg yolk	1 extra	This is your secret weapon for richness
All-purpose flour	1½ cups	Gives structure to the cookie dough
Baking powder	1 tsp	Just a tiny lift
Salt	1 pinch	Balances out all that sweetness
Graham cracker crumbs	2/3 cup (about 9 sheets)	The essential s’mores flavor
Mini marshmallows	1 cup, divided	Creates that gooey filling
Chocolate chunks	1/2 cup, chopped fine	Melts way better than chips
Hershey’s bars	2 full-sized	Classic s’mores chocolate—accept no substitutes

The Sugar Situation

Why both kinds of sugar?

Brown sugar keeps everything soft and chewy on the inside. White sugar helps those edges get crispy and golden. Together? Magic.

About That Extra Egg Yolk

I know it seems weird to add just a yolk. But trust me on this. That extra yolk makes the dough incredibly rich without making it heavy or cakey. It’s the difference between good and “oh my god where has this been all my life.”

Chunks Over Chips

I always use chocolate chunks instead of chips. They melt more evenly and create these amazing pockets of melted chocolate throughout the casserole.

Can’t find chunks? Chips will work. The dessert police won’t arrest you.

Ways to Mix Things Up

The basic version is phenomenal. But here’s how I like to customize it:

The Peanut Butter Route Swap out the middle Hershey’s layer for chopped Reese’s Peanut Butter Cups. Cut them up just like you would the chocolate bars. The peanut butter-marshmallow combo will blow your mind.

Go Silky Smooth Replace those mini marshmallows in the middle with marshmallow fluff. Spread it carefully over the first dough layer. You get a smoother, silkier center that way.

Extra Decadent Version Before you add the marshmallows, spread a thin layer of caramel sauce over that first dough layer. Or use cream cheese. Either one adds this whole other dimension of flavor.

Dark Chocolate Twist Use dark chocolate instead of milk chocolate for everything. It cuts the sweetness a bit. Perfect if you’re not a huge sugar person.

The basic recipe? Already incredible. These variations just let you make it your own.

Let’s Actually Make This Thing

Okay, enough talking. Time to bake.

Don’t worry if you’re new to this. I’ve broken everything down into super simple steps. Even my friend who “can’t bake” nailed this on her first try.

Get Your Kitchen Ready

First up: turn that oven to 350°F.

While it’s heating, grab your 8×8 inch baking pan. You’ve got two options here—either spray it really well with cooking spray, or line it with parchment paper.

I’m team parchment all the way. Cleanup is so much easier.

Critical warning: Don’t skip this step. Baked marshmallows are like superglue. Without proper prep, you’ll be scraping and scrubbing for days. Learn from my mistakes.

Making the Cookie Dough

Grab a microwave-safe glass bowl. Toss in your butter. Microwave it in 30-second bursts until it’s completely melted.

Let it cool for a minute or two. If it’s too hot, it’ll cook your eggs when you add them. Not what we want.

Dump both sugars into that melted butter. Get your electric mixer and beat them together until smooth. Takes about 1-2 minutes. The mixture should look lighter in color and smooth.

Now add your egg, that extra yolk, and vanilla extract. Beat it all together. The mixture will get thick and glossy.

Perfect.

Time for dry ingredients. Add the flour, baking powder, salt, and about 1/3 cup of those graham cracker crumbs. Mix on low speed. Stop the second you don’t see any more flour streaks.

Don’t overmix. Seriously. Overmixing makes tough, dense desserts. We want tender and chewy.

Fold in half a cup of mini marshmallows and all your chocolate chunks. Use a rubber spatula. Gentle folding motions. This keeps everything tender while getting the mix-ins distributed evenly.

Building the Layers (This Is Where It Gets Fun)

Take half your cookie dough. Press it into the bottom of your prepared pan. Use your hands or the back of a spoon. Doesn’t need to be perfect. Just aim for fairly even.

Break up one Hershey’s bar into pieces. Scatter them over the dough. They can overlap a bit—that’s fine.

Sprinkle your remaining half cup of mini marshmallows over those chocolate pieces. Press them down gently with your fingertips. This keeps them from floating around during baking.

Now for the tricky part.

Take your remaining cookie dough and spread it over the marshmallow-chocolate layer. The dough is thick, so this takes patience. Drop small blobs across the surface. Then gently press and spread to cover everything.

You might think “this isn’t working.” Keep going. It works.

Finally, grab that remaining 1/3 cup of graham cracker crumbs. Press them into the top layer. This creates the signature crunchy topping.

Into the Oven

Slide your pan into that preheated oven. Set a timer for 22 minutes.

What you’re looking for:

• Edges pulling slightly away from the pan
• Top that’s golden brown
• Center that looks set (not jiggly)

The second it comes out of the oven, break up your second Hershey’s bar. Lay those pieces right on top of the hot casserole. The heat will soften them into this gorgeous glossy finish.

Now comes the hardest part.

Waiting.

I know. I know you want to dig in right now. But you need to let this cool for at least 15-20 minutes. Otherwise it falls apart when you try to cut it.

The layers need time to set properly.

How to Serve This Bad Boy

Once it’s cooled, grab a sharp knife. Cut nine generous squares.

Want to take it over the top? Serve each piece warm with vanilla ice cream. The cold ice cream hitting that warm, gooey casserole is next level.

You can also add:

• Whipped cream on top
• A drizzle of chocolate sauce
• A sprinkle of sea salt for that sweet-salty thing

Some people even do all three. No judgment here.

Storage, Tips, and Your Burning Questions

Keeping It Fresh

This casserole stores like a dream. That’s why it’s perfect for bringing to potlucks or making ahead for parties.

Room temperature: Store in an airtight container for up to 5 days.

In the fridge: If your kitchen is hot, refrigerate it. Lasts a full week that way.

Reheating Magic

Want that fresh-baked experience again?

For one piece: Microwave for 15-20 seconds. The chocolate and marshmallows get gooey again.

For the whole pan: Cover with foil. Warm in a 300°F oven for 5-10 minutes. Boom—tastes like you just made it.

Tips That’ll Save Your Life

Always grease or line that pan. I can’t say this enough. Sticky marshmallow is impossible to clean from an ungreased pan. Don’t test me on this.

Chocolate chunks are worth finding. Yeah, chips work. But chunks create way better melty pockets. Check your grocery store’s baking aisle.

Don’t overbake it. The casserole keeps cooking a bit after you pull it from the oven. Take it out when the edges look done, even if the center seems barely set.

Wait before cutting. Warm casserole = falling apart mess. Cooled casserole = clean, perfect squares.

Crushing graham crackers: Toss whole crackers in a sealed plastic bag. Roll over them with a rolling pin. Perfect crumbs every time.

Your Questions Answered

Can I prep this ahead?

Absolutely. Assemble the whole thing up to the baking step. Cover tight with plastic wrap. Refrigerate up to 24 hours.

When you’re ready to bake, let it sit at room temperature for 15 minutes first. Then bake as normal. Might need an extra 2-3 minutes since it’s starting cold.

I only have big marshmallows. Now what?

No sweat. Grab some kitchen scissors and cut each large marshmallow into four pieces.

Pro tip: spray those scissors with cooking spray first. Otherwise the marshmallows stick like crazy.

How do I get clean cuts?

Use a sharp chef’s knife. Wipe it clean between each cut.

For really clean edges? Run the knife under hot water. Dry it quick. Then make your cut. The warmth helps it glide through all those sticky layers.

Works like a charm.

Can I add toasted marshmallows on top?

Oh yeah. Here’s how:

During the last 1-2 minutes of baking, pull out your pan. Scatter more mini marshmallows across the top. Switch your oven to broil.

Put the pan back in for 30-60 seconds. Watch it like a hawk—marshmallows burn fast under the broiler.

Golden and toasted? Perfect.

Why did my middle layer disappear?

This happens when the top dough layer is too thin or spread unevenly. The marshmallows and chocolate push up through the gaps.

How to fix it: take your time with that second dough layer. Cover the entire surface. Yeah, it’s tedious. But it’s worth it.

Can I double this?

Sure can. But use a 9×13 inch pan instead of making two separate pans. Add 5-7 minutes to the baking time. Check doneness by looking at the edges and poking the center with a toothpick.

Final Thoughts

Look, I’ve made a lot of desserts over the years.

This S’mores Casserole? It’s in my top five. Maybe top three.

Everything you love about campfire s’mores—the gooey marshmallows, melted chocolate, crunchy graham crackers—all in one easy-to-share dessert. No fire required.

I’ve brought this to summer barbecues, winter dinner parties, office potlucks, and random Tuesday nights when I just wanted something amazing.

It disappears. Every. Single. Time.

Someone always asks for the recipe. Someone always goes back for seconds. And someone always suggests we make it again next week.

Give it a shot. Seriously.

You’ll be making this one again and again.