Position rack in lower 1/3 of oven. Preheat to 350. Line baking sheet with parchment or waxed paper. Cream butter with sugar, beat in coffee. Add flour and walnuts blending well. Place dough in pastry bag or cookie gun with 1/2" tip and pipe into 2" lengths on baking sheet. Dough will be stiff. Bake until golden brown - about 10 - 15 minutes. Cool on rack. dip each end of cookie into melted chocolate and then into sprinkles or nuts if desired. Let dry on wax paper. Store in airtight container. Very delicate cookie but so delicious.