Preheat oven to 180 degrees C. Grease two 12 cup muffin pans or line with 18 paper patty cups.
In a medium bowl, beat the margarine and sugar with an electric mixer until light and fluffy. Mix in the eggs, one at a time, then stir in vanilla, instant coffee and cayenne pepper. Combine the flour, cocoa, baking powder, bicarb soda and salt; stir into the batter, alternating with the water, just until blended. Spoon the batter into the prepared cups, dividing evenly.
Bake in the preheated oven until the tops spring back when lightly pressed, 20 to 25 minutes. Cool in the pan set over a wire rack. When cool, arrange the cupcakes on a serving platter and ice as desired.