Preheat oven to 350. Lightly spray 2 muffin tins.

Cream together butter and sugars until fluffy. Mix in vanilla and egg.

In separate bowl combine flour, baking soda, and cocoa.

Add dry to wet and stir to combine. Fold in pieces.

Put walnut size balls of dough in each muffin cup.

Bake about 8 or 9 minutes. Cookies will still be soft but will firm up as they cool. Let them cool before trying to remove from tins. I used an icing spatula to pop them up and out....