Gather all your ingredients.
Cream together butter and sugars.
Once that is creamed together, beat in your eggs and vanilla.
Now combine your flour, cocoa powder, baking soda and salt in a separate bowl.
Slowly mix in your dry ingredients to your wet ingredients. The dough will be very thick but keep mixing!
It should look something like this^ You can also taste test if you don't mind taking a risk...I know I did!
Okay, now this is probably the hardest part- refrigerate the dough for at least 30 minutes.
After 30 mins, preheat your oven to 375 degrees F, and pour graham cracker crumbs into a bowl.
Roll about 1 tbsp of dough into a ball and flatten. Place half a marshmallow inside the dough.
Cover with another ball of flattened dough, and press edges together, fully covering the marshmallow. Roll it into a ball.
Cover the dough completely with the graham cracker crumbs.
Repeat for the rest of the dough and place balls onto a baking sheet lined with parchment paper.
Bake for 8-10 minutes. Cookies should look puffy and be slightly underdone. Allow to cool on trays for 5 mins.
Transfer cookies to a wire rack to cool completely. Store in an airtight container, if you have any extras;)