Unsalted Butter Granulated Sugar Egg Vanilla Extract All Purpose Flour Cocoa Powder Baking Soda Salt Chocolate Chunks Mini Marshmallows
In a large bowl, cream butter and sugar together, then add egg and vanilla extract. Mix to combine. Add flour, baking soda, cocoa powder and salt. Mix well to combine. Fold in chocolate chunks.
Roll dough into 1.5-inch balls, press 3-4 marshmallows onto the top of each of them, then place them on a cookie sheet. Make sure to secure the marshmallow well if not it could fall out during baking.
Bake at 350°F for 9-10 minutes. Check at the 9-minute mark. Let cookies sit on baking sheet for 2-3 minutes before carefully removing them and placing them onto a baking rack to cool for 10 minutes.