Name: Gooey S’mores Cake Bars
Prep time: 10 min
Cook time: 20 min
Total time: 30 min
Cuisine: American
Ingredients: 1 box yellow cake mix (just the dry mix); 1 large egg; 1/2 cup butter, melted; 1 cup graham cracker crumbs; 1 cup marshmallow crème (store-bought or homemade); 1 1/2 cups milk chocolate chips; 1 1/2 cups mini marshmallows

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These Gooey S’mores Cake Bars are the ultimate indoor version of the classic campfire treat. Built on a soft, graham cracker-infused cake crust and layered with milk chocolate, marshmallow crème, and gooey mini marshmallows, these bars are everything I love about s’mores—minus the mess and smoke. They’re rich, nostalgic, and ridiculously easy to make.

Why You’ll Love This Recipe

I love this recipe because it’s quick, simple, and delivers that classic s’mores flavor in a handheld dessert bar. There’s no fire required, and I can enjoy these treats year-round. The cake mix gives the base a soft yet chewy texture, while the graham cracker crumbs give it that essential s’mores flavor. It’s the perfect treat to bring to potlucks, serve at parties, or enjoy with the family on a relaxed weekend. Gooey S’mores Cake Bars

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

yellow cake mix (just the dry mix)
egg
butter, melted
graham cracker crumbs
marshmallow creme
milk chocolate chips
mini marshmallows

Directions

Preheat the oven
I set my oven to 350°F and lightly grease a 9×13-inch baking dish or line it with parchment paper.
Make the crust
In a large bowl, I combine the dry cake mix, egg, melted butter, and graham cracker crumbs. I mix everything until it forms a thick dough. This will act as the base and topping for the bars.
Press into the pan
I take about two-thirds of the dough and press it evenly into the bottom of the prepared pan to form the crust.
Layer the fillings
I gently spread the marshmallow crème over the crust (using a spoon or offset spatula works best), then sprinkle the chocolate chips evenly on top. I finish by scattering the mini marshmallows over the chocolate.
Add the topping
I crumble the remaining dough over the top of the marshmallows, pressing it down slightly but leaving some pockets exposed for that gooey texture.
Bake
I bake the bars for about 20 minutes, or until the top is lightly golden and the marshmallows are just starting to toast.
Cool and slice
I let the bars cool completely before slicing into squares. This helps them set and keeps the layers distinct and gooey.

Servings and timing

This recipe makes 24 bars.
Prep Time: 10 minutes
Cook Time: 20 minutes
Total Time: 30 minutes

Variations

I like to mix it up from time to time with these ideas:

Use dark chocolate chips for a richer flavor.
Add chopped nuts like pecans or walnuts to the crust for crunch.
Use chocolate cake mix instead of yellow for a double chocolate twist.
Add peanut butter chips for a fun s’mores-peanut butter combo.

Storage/Reheating

I store leftovers in an airtight container at room temperature for up to 4 days. For longer storage, I refrigerate them—just let them come to room temperature before serving. If I want to warm them slightly before eating, I pop them in the microwave for 10–15 seconds to bring the gooey texture back to life.

FAQs

Can I use homemade marshmallow fluff instead of store-bought?

Yes, if I have homemade fluff on hand, it works beautifully. I just make sure it’s soft and spreadable for easy layering.

What’s the best way to spread marshmallow crème?

It can be sticky, so I use a spoon or spatula coated lightly with cooking spray or a bit of warm water to help spread it evenly.

Can I freeze these bars?

Yes, I freeze them once cooled and cut into squares. I wrap them in plastic wrap and place them in a freezer-safe container. They keep well for up to a month.

Can I make these gluten-free?

Absolutely. I use a gluten-free cake mix and certified gluten-free graham crackers to make a gluten-free version that tastes just as good.

Can I double this recipe?

Yes, I double it and bake in two 9×13-inch pans or one large baking sheet. Just make sure the dough layers aren’t too thick so everything bakes evenly.

Conclusion

Gooey S’mores Cake Bars are everything I want in a dessert: easy, nostalgic, and loaded with melty chocolate and marshmallow goodness. Whether I’m making them for a get-together or just craving a cozy treat at home, these bars always deliver. They’re the kind of crowd-pleasing dessert that disappears fast—and the kind I find myself making again and again.