Ooey Gooey S'mores Bars are a delicious treat inspired by campfire s'mores with melty marshmallow, a buttery graham cracker crust, and a rich-sweet chocolate. These satisfying and easy to make bars are irresistible!
Preheat the oven to 350 degrees Fahrenheit. Line an 8x8-inch pan with aluminum foil or parchment paper.
In a food processor, pulse the 9 sheets graham crackers until finely ground without any lumps. Combine the crumbs with the 1 cup + 2 tablespoons all-purpose flour and ½ teaspoon salt and set aside.
Whisk the 1 cup softened butter and ⅔ cup brown sugar until light and fluffy, then add the 1 teaspoon vanilla extract.
Add the graham cracker and flour mixture to the butter mixture and mix until incorporated.
Press ⅔ of the dough into the bottom of the 8x8-inch pan and lay the 3 ½ Hershey's chocolate bars evenly across the crust.
Using a small spoon, dollop the 3 ½ ounces marshmallow fluff, evenly on top of the chocolate layer. Crumble the remaining dough on top, lightly patting the dough flat to spread and flatten. Some of the marshmallow will peek through.
Bake for 30-35 minutes until the top is golden brown and toothpick comes out clean. Let them completely cool before cutting. They can still be a little warm and are amazing!