Preheat oven to 350 degrees. Use parchment paper or a silpat mat to line a baking sheet.
Cream the butter, brown sugar and granulated sugar in a stand mixer until light and fluffy (about 2-3 minutes). Scrape the sides of the bowl to make sure all ingredients are blended.
Add in eggs, vanilla and cold coffee and beat until combined.
Add in flour, cocoa, and baking soda. Mix until all combined.
Stir in semi-sweet chocolate chips.
Scoop out dough and roll into balls. Depending on the size of cookies you want, scoop out 1/4 cup dough for BIG cookies or 2 TBSP dough for smaller cookies. Place dough balls on prepared pan (6 cookies to a pan) and flatten with your hand to about 1/2 inch thick.
Bake for 9-10 minutes. Cool cookies cookie sheet for 10 minutes before removing to cooling rack.
While cookies are cooling, make the frosting.
Chocolate Fudge Frosting
In stand mixer, cream butter, powdered sugar, vanilla extract and cocoa for about 2-3 minutes until smooth.
Add in melted chocolate and mix for an additional 2-3 minutes until the frosting is light and fluffy. NOTE: The color of the frosting will get lighter the longer you mix. That's okay.
Put the frosting in a piping bag with a star tip OR you can put the frosting in a gallon size Ziploc bag and cut off one corner of the bag. Use the frosting bag to pipe frosting in a spiral on top of the cooled cookies.