To begin, in a saucepan combine coffee and butter. Melt this together over low heat until just melted. Remove from heat.
In your mixing bowl, combine flour, baking powder, baking soda, salt, baking cocoa, brown sugar, and instant espresso powder. Stir those together and set aside for now.
Separate the eggs into two different bowls. Beat the egg whites with an electric beater until soft glossy peaks form. Beat the yolks until smooth.
Back to your dry ingredients - Add in the coffee-butter mixture, egg yolks, and milk. Mix until smooth.
Gently fold the egg whites into your rich batter.
When just combined, prepare these waffles in your waffle maker according to its instructions. This makes about 7 – eight inch “Belgian” style waffles.
Because these waffles are not terribly sweet, you can top them with whatever you like. I like going with a dusting of powdered sugar, fresh strawberries, and a drizzle of chocolate syrup.