Heat your oven to 350 (180C) and grease or spray a 12-count muffin pan. This recipe will make 12 muffins.
Sift the flour, baking powder and cocoa powder into a mixing bowl then stir in the brown sugar.
In another mixing bowl mix you egg, milk, canola oil and espresso. Give your white chocolate a good chop either on a chopping board or by pulsing in a food processor. Add this to the wet ingredients.
Mix until just combined and spoon into the holes in your muffin pan. Bake them for 20 minutes or until the muffin springs back lightly when pressed. Cool in pan for 5 minutes before turning out.