For the cookies: cream together the butter and sugar with a handheld mixer until fluffy in a bowl. In a separate bowl, beat egg yolks, then beat in the extracts and cinnamon. Add the beaten egg yolk mixture to the creamed butter and sugar and blend well. Whisk together the flour, baking soda, cocoa powder and cream of tartar. Add the dry ingredients to the wet mixture, mix until well blended. Take a spoonful into your palm and form into 1-inch balls. Roll them in sugar and place on a greased cookie sheet. Slightly flatten before placing in the preheated oven. Bake at 350 degrees F until firm and slightly golden at the edges, 12 to 15 minutes.
For the topping: whisk together the sugar, cocoa, chili powder and cinnamon for the topping.
Dust cookies with topping while still warm.
Recipe courtesy of Angry Birds