1. If desired, line cookie sheets with parchment paper; set aside. In a large bowl, stir together flour, granulated sugar, baking powder, cocoa, cinnamon, and cloves. Using a pastry blender, cut in butter until mixture resembles coarse crumbs. Make a well in the center of the flour mixture.
2. In a medium bowl, whisk together eggs, cooled coffee, and vanilla. Pour egg mixture into flour mixture and stir to combine. Stir in nuts. If necessary, cover and chill dough until easy to handle (1 to 2 hours).
3. Preheat oven to 375 degrees F. Shape dough into walnut-sized balls (about 1 1/4 inches in diameter). Place balls about 2 inches apart on ungreased or parchment-lined cookie sheets. Bake for 8 to 10 minutes or until edges are firm. (Cookies may still appear soft. Do not overbake.) Transfer cookies to a wire rack and let cool. Drizzle with icing. Let icing dry. Makes about 3 dozen cookies.
4. Powdered Sugar Drizzle: In a small bowl, stir together 1 cup powdered sugar and enough milk (1 to 2 tablespoons) to make an icing of drizzling consistency.
5. To Store: Layer cookies between waxed paper in an airtight container; cover. Store at room temperature for up to 3 days. Or freeze unfrosted cookies for up to 3 months; thaw cookies and frost.