Preheat oven to 190 degrees C. Place bacon in a large, deep frypan. Cook over medium-high heat until evenly brown. Drain, dice and set aside.
In a large bowl, stir together the flour, 3/4 cup cocoa powder, sugar, bicarb soda, baking powder and salt. Make a well in the centre and pour in the eggs, coffee, buttermilk and oil. Stir just until blended. Mix in 3/4 of the bacon, reserving the rest for garnish. Spoon the batter into greased muffin cups, dividing evenly.
Bake in the preheated oven until the tops spring back when lightly pressed, 20 to 25 minutes. Cool in the tin on top of a wire rack. When cool, arrange the cupcakes on a serving platter. Ice with your favourite chocolate icing and sprinkle reserved diced bacon on top. Dust with additional cocoa powder.