Name: S’mores Cookie Bars
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Cuisine: American
Ingredients: 1 cup unsalted butter, softened; 1 cup light brown sugar, packed; ½ cup granulated sugar; 2 large eggs; 2 tsp vanilla extract; 2¾ cups all-purpose flour; 2 tsp cornstarch; 1 tsp baking soda; ½ tsp salt; 1 cup graham cracker crumbs (about 8 full crackers); 1½ cups semi-sweet chocolate chips; 2 cups mini marshmallows

Why You’ll Love This Recipe

I love how these cookie bars capture all the nostalgic flavors of s’mores in a much less messy, easier-to-make format. They’re sweet, chewy, and indulgent, with layers of graham cracker cookie dough, chocolate chips, and gooey marshmallows. They’re always a hit with both kids and adults.

ingredients

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

1 cup unsalted butter, softened
1 cup light brown sugar, packed
½ cup granulated sugar
2 large eggs
2 teaspoons vanilla extract
2¾ cups all-purpose flour
2 teaspoons cornstarch
1 teaspoon baking soda
½ teaspoon salt
1 cup graham cracker crumbs (about 8 full crackers, crushed)
1½ cups semi-sweet chocolate chips
2 cups mini marshmallows

directions

I begin by preheating the oven to 350°F (175°C) and lining a 9×13-inch baking pan with parchment paper, leaving an overhang to make removal easy.

In a large bowl, I cream together the softened butter, brown sugar, and granulated sugar until the mixture is light and fluffy—this takes about 2 to 3 minutes.

Then I beat in the eggs one at a time and add the vanilla extract.

In another bowl, I whisk together the flour, cornstarch, baking soda, salt, and graham cracker crumbs.

I gradually add the dry mixture into the wet ingredients, mixing until everything is just combined. Then I gently fold in the chocolate chips.

Next, I spread half of the dough evenly into the prepared pan. I sprinkle the mini marshmallows evenly over this layer.

I crumble the remaining dough over the top, making sure most of the marshmallows are covered.

I bake the bars for 25 to 30 minutes, until the edges are golden and the marshmallows are puffed.

After baking, I let the bars cool in the pan for at least 15 minutes before lifting them out and slicing into 24 pieces.

Servings and timing

This recipe yields 24 cookie bars.
Prep Time: 15 minutes
Cooking Time: 30 minutes
Total Time: 45 minutes
Calories: 290 kcal per bar

Variations

Sometimes I swap out the chocolate chips for milk chocolate chunks to get that true s’mores flavor. I’ve also mixed crushed pretzels into the dough for a salty twist or added a swirl of peanut butter for even more indulgence.

storage/reheating

I keep these bars in an airtight container at room temperature for up to 4 days. They refrigerate well and can also be frozen for up to 2 months. To reheat, I microwave a piece for about 10 seconds to bring back the gooey texture.

FAQs

Can I use jumbo marshmallows instead of mini?

I prefer mini marshmallows because they distribute more evenly, but I can chop jumbo ones into smaller pieces if that’s what I have.

Why use graham cracker crumbs in the dough?

They give the bars that signature s’mores flavor and make the cookie base more tender and flavorful.

Can I make these ahead of time?

Yes, I often bake them the night before and they taste just as good the next day.

How do I keep the marshmallows from burning?

I make sure they’re mostly covered by the top layer of dough before baking, which keeps them gooey and golden, not burnt.

Can I double this recipe?

Yes, I double everything and bake it in two 9×13 pans or one large sheet pan, adjusting the baking time slightly.

Conclusion

These s’mores cookie bars are my go-to for an easy, crowd-pleasing dessert. They’re rich, chewy, and loaded with all the gooey, chocolatey goodness I expect from a classic s’more—no campfire required. Whether I’m baking for a party or just for fun, these never last long.

S’mores Cookie Bars