1-First, preheat your oven to 325°F and line a 9”×13” baking pan with parchment paper, leaving some overhang for easy removal trust me, this little tip makes cleanup a breeze! Next, mix the graham cracker crumbs with ½ cup of melted salted butter and press it evenly into the pan bottom, then pop it in the freezer while you prepare the dough. In a large bowl, beat together 1 cup granulated sugar, 1 ¼ cups packed brown sugar, and ¾ cup melted unsalted butter until smooth, then add 3 large eggs one at a time, followed by 1 ½ teaspoons vanilla extract.

2-Mixing and Baking Steps: In a separate bowl, whisk 3 cups of all-purpose flour (spooned and leveled), 2 ½ teaspoons baking powder, and 1 teaspoon fine sea salt. Gradually add this dry mixture to the wet ingredients on low speed until combined. Fold in 1 cup semi-sweet chocolate chips and 1 cup mini marshmallows, then spread the dough evenly over the chilled crust using an offset spatula.

3-Top the dough with pieces from 1 to 2 plain chocolate bars, broken graham cracker pieces, and ½ cup mini marshmallows, pressing them in slightly for that perfect hold. Bake for 35-45 minutes until the top is golden brown and no wet batter remains keep an eye on it to get it just right! Once done, cool completely for at least 1 hour before cutting; run a knife around the edges, lift with the parchment, and cut on a board for neat squares.