1. Preheat oven to 350 degrees. Cream butter, brown sugar & granulated sugars together until fluffy using a stand mixer with a paddle attachment.
Add eggs one at a time. With mixer on low add ground coffee and vanilla extract. Add the flour mixture until well blended. Sprinkle in cayenne pepper and cocoa and mix well.
2. Stir in chopped chocolate. Chill dough for 1 hour before baking. Drop rounded tablespoons of dough onto cookie sheets lined with parchment paper about 2 inches apart after dipping tops of dough balls in decorative sugar crystals.
3. Bake until cookies are puffy and the surface starts to “crack,” about 10-12 minutes. Sprinkle on more decorative sugar & extra cayenne if desired while cookies are hot, cool on wire racks. Cookies will keep for up to one week stored in airtight containers with waxed paper between layers. Yield: 36 cookies