S'mores Cake Mix Cookie Bars
S'mores Cake Mix Cookie Bars are soft, chewy dessert bars made from a simple yellow cake mix cookie base loaded with graham crackers, chocolate chips, mini marshmallows, and Hershey’s chocolate pieces on top. Baked in a 9×9 pan, they come together in one bowl, use basic pantry ingredients, and deliver classic s’mores flavor in under an hour.
Ingredients
- 1 box yellow cake mix 15.25 ounces
- 2 eggs
- 1/2 cup (1 stick) unsalted butter melted
- 3/4 cup semisweet chocolate chips
- 4 to 5 full graham cracker sheets divided
- 1 1/2 - 2 cups mini marshmallows
- 2 Hershey’s milk chocolate bars divided
Instructions
- Preheat the oven to 350°F. Line a 9×9-inch baking pan with parchment paper, leaving some overhang for lifting out the bars.
- Break the graham crackers into bite-sized pieces. Chop one Hershey’s bar into smaller pieces and set it aside for the topping. Leave the second chocolate bar whole for the final step.
- Add the yellow cake mix, eggs, and melted butter to a large mixing bowl. Stir until completely combined and a thick cookie dough forms.
- Fold the semisweet chocolate chips and about 3 graham cracker sheets’ worth of pieces into the dough. Reserve the remaining graham cracker pieces for the topping.
- Press the dough evenly into the prepared pan, making sure it reaches the corners. Bake for 20–24 minutes, until the edges are lightly golden and the center looks almost completely set.
- Remove the pan from the oven, but leave the oven on. Sprinkle the mini marshmallows, chopped Hershey’s chocolate, and remaining graham cracker pieces over the warm cookie base.
- Return the pan to the oven for 3–5 minutes, until the marshmallows are soft and puffy and the chocolate begins to melt.
- If desired, switch the oven to broil. Broil for about 20–30 seconds, watching constantly, until the marshmallows are lightly toasted.
- Break the remaining Hershey’s bar into individual rectangles. While the bars are still warm, gently press the rectangles into the topping. The residual heat will soften the chocolate and help it stick.
- Let the bars cool in the pan until firm enough to lift. Transfer the slab to a cutting board using the parchment overhang and allow it to finish cooling before cutting into 9 large squares or 12 smaller bars.