For best results, use a kitchen scale when measuring the ingredients.
Whisk together the flour, cocoa powder, baking soda, baking powder, and salt. Set aside.
208 grams all purpose flour, 40 grams dutch processed cocoa powder, 1 teaspoon baking soda, ½ teaspoon baking powder, ½ teaspoon salt
Coarsely chop the chocolate, then break apart the graham crackers into small pieces and crumbs. Set aside.
4 oz bittersweet or dark chocolate, 60 grams graham cracker pieces & crumbs
Combine the wet ingredients - vigorously whisk together the melted butter, brown sugar, & granulated sugar until well combined. Add the egg, egg yolk, & vanilla extract and whisk to combine.
170 grams unsalted butter, 150 grams light brown sugar, 100 grams granulated sugar, 1 egg, 1 egg yolk, 1 tablespoon pure vanilla extract
Add about two thirds of the dry ingredients and fold until only a few streaks of flour are remaining - it should kind of look like brownie batter at this point. Add the graham crackers, chocolate, and remaining dry ingredients and fold until evenly combined.
Cover the bowl tightly and refrigerate for at least one hour.
Scoop the dough into large balls measuring 85 grams. Flatten the dough in between your palms, then put a marshmallow (long side down) in the center. Fold the dough up & around the marshmallow but leaving a little peaking through - see pictures in post for reference.
10-12 regular sized marshmallows
Space them 2-3 inches apart on a baking sheet, cover, and refrigerate for another 1-2 hours.
Once ready to bake, preheat the oven to 350F and line a baking sheet with parchment paper.
Bake the cookies for 10-11 minutes until the marshmallows have puffed up and the cookies have spread open around it but with set edges. To make each cookie perfectly circular, use a large round cookie cutter or bowl to gently scoot the edges in. Return to the oven for an additional minute or so.
Remove the cookies from the oven & let the tray cool on a wire rack or trivet for 5 minutes. Sprinkle more graham crackers & chocolate on top. Then carefully remove them from the pan with a spatula. Enjoy warm (my preference) or let cool completely on a baking rack. Store in an airtight container at room temperature.