Mix cold butter and sugars till just combined and no large chunks are remaining
Add egg yolks, egg, and vanilla
In a separate bowl, combine dry ingredients (sift cocoa powder)
Add dry ingredients to wet mixture, half at a time, being careful not to over-mix
Add peppermint chips and semi-sweet chocolate chips
Shape dough into 4 oz towers
Freeze overnight or until solid (around 3 hours)
Bake at 350F for 15-20 minutes
