01 -
Start by preheating the oven to 350 degrees.
02 -
Cream butter, white sugar, and brown sugar together in a medium sized mixing bowl.
03 -
Add egg and vanilla and mix well.
04 -
In a mixing bowl, use a fork or whisk to combine flour, baking cocoa, baking soda, and salt and then add the dry mixture to the wet mixture.
05 -
Fold in chocolate chunks.
06 -
Using a cookie scoop, create 2 tablespoon cookie dough balls and place them about 2" apart on a baking sheet that has been lined with parchment paper.
07 -
Press 3 marshmallows into the center of each cookie dough ball and bake for 9-10 minutes.
08 -
Remove from the oven and add 3-6 more marshmallows and use them to spread the melted marshmallows around the top of the cookie.
09 -
Place a piece of chocolate on top of the marshmallows and sprinkle with crushed graham crackers.