01 -
Heat the oven to 350°F and get it ready.
02 -
In a medium bowl, mix together the soft butter, both sugars, and cream them together until smooth.
03 -
Stir in the egg and vanilla extract. Keep mixing until combined.
04 -
In a new bowl, stir flour, cocoa powder, salt, and baking soda with a whisk or fork. Slowly bring the dry ingredients into the butter-sugar mixture.
05 -
Gently fold the chocolate chunks into the dough.
06 -
Use a cookie scoop to make dough balls (roughly 2 tablespoons each). Put them 2 inches apart on a sheet with parchment paper.
07 -
Press 3 mini marshmallows into the middle of each ball before putting the tray into the oven. Bake them for about 9-10 minutes.
08 -
Take the cookies out and quickly put 3-6 more marshmallows on each. Spread the melted marshmallows over the tops.
09 -
Break up pieces of a Hershey bar and place some on the marshmallow tops. Dust with graham cracker crumbs to finish.