Preheat oven to 400 degrees. Sift together flour, cocoa powder, cream of tartar, baking soda, and salt. In a separate bowl beat together butter and 1 1/2 cups sugar until fluffy, add eggs. On low speed gradually add flour mixture. In a small bowl combine remaining sugar, cinnamon, and chile powder. Form 1" balls of dough and roll in mixture. Bake for 10 minutes. Dig in!