Ooey Gooey S'mores Cookie Bars
These Ooey Gooey S'mores Cookie Bars layer buttery graham cracker cookie dough with melted milk chocolate and toasted mini marshmallows for the ultimate campfire-inspired dessert. Easy to make in one pan with simple pantry ingredients, they come together in under 45 minutes. Perfect for parties, bake sales, or any occasion that calls for something seriously delicious.
Equipment
- 9x13-inch baking pan
- Parchment paper
- Large mixing bowl
- Whisk
- Rubber spatula
Ingredients
- 1 cup unsalted butter melted and slightly cooled
- 1 cup brown sugar packed
- 1/2 cup granulated sugar
- 2 large eggs room temperature
- 2 teaspoons pure vanilla extract
- 1 1/2 cups all-purpose flour
- 1 1/2 cups graham cracker crumbs finely crushed, about 12 full crackers
- 1 teaspoon baking powder
- 1/2 teaspoon salt
- 1 1/2 cups milk chocolate chips or chopped milk chocolate bars
- 2 cups mini marshmallows
Instructions
- Preheat your oven to 350°F (175°C). Line a 9x13-inch baking pan with parchment paper, leaving a 2-inch overhang on the long sides to use as handles for easy removal later.
- In a large mixing bowl, whisk together the melted butter, brown sugar, and granulated sugar until smooth and well combined. The mixture should look glossy and uniform.
- Add the eggs and vanilla extract to the butter-sugar mixture and whisk vigorously until fully incorporated and the batter is smooth and slightly lightened in color.
- Add the flour, graham cracker crumbs, baking powder, and salt to the bowl. Using a rubber spatula, fold until a soft, cohesive dough forms with no dry streaks remaining. Do not overmix.
- Divide the dough roughly in half. Press one half evenly into the bottom of the prepared pan. Use lightly dampened fingers or the flat bottom of a measuring cup to create an even, smooth layer.
- Scatter the milk chocolate chips evenly over the dough base, then spread the mini marshmallows in an even layer on top of the chocolate, covering as much surface area as possible.
- Drop small spoonfuls of the remaining dough over the marshmallow layer. Gently flatten each piece slightly and press down. It is perfectly fine if marshmallows peek through the gaps; this creates the signature gooey, rustic look.
- Bake for 25 to 30 minutes, until the top is golden brown and the marshmallows are puffed and lightly toasted. The center may look slightly underset but will firm up as it cools. If the marshmallows brown too quickly in the last few minutes, tent the pan loosely with foil.
- Remove from the oven and allow the bars to cool in the pan on a wire rack for at least 20 minutes. For the cleanest cuts, refrigerate for an additional 10 minutes before using the parchment overhang to lift the slab out and slicing into 16 bars.
Notes
For the cleanest slices, use a sharp knife wiped with a damp cloth between cuts. Bars can be stored in an airtight container at room temperature for up to 4 days, refrigerated for up to 1 week, or frozen (individually wrapped) for up to 2 months. Reheat in the microwave for 15 to 20 seconds to restore gooeyness. Avoid overbaking as the bars will continue to set as they cool.