Cream together butter, sugars and molasses until light and fluffy.
Beat in egg and peppermint flavoring
In a separate bowl whisk together flour, baking soda, salt and cocoa.
Add flour mixture to butter/sugar mixture one cup at at time mixing well after each addition. Add in chocolate chips.
Put the dough on plastic wrap form into a disk shape, not too thick. Wrap well and chill in the fridge at least 2 hours or over night. If you have a shorter chilling time form the dough into two smaller disc shapes.
Preheat oven to 325f
After dough is well chilled form into small 1 1/2 balls. If desired dip cookies in sugar. Place on a greased or parchment lined cookie sheet and bake for 10 - 15 minutes until tops of the cookies slightly crack. Cool for 5 minutes than transfer to a rack to finish cooling.
Enjoy!