Preheat oven to 180°C. Lightly grease a 6-hole, 3/4-cup capacity non-stick muffin pan.
Make basic muffin mix Sift flour into a large bowl. Add caster sugar and stir to combine. Make a well in the centre. Combine milk, egg, butter and coffee (see tip) in a jug. Pour milk mixture into the well. Using a large metal spoon, stir until just combined (don't over-mix).
Spoon mixture into muffin holes until three-quarters full. Bake for 25 minutes or until a skewer inserted into the centre comes out clean. Allow to cool in pan for 1 minute. Turn out onto a wire rack to cool.
Using an electric mixer, beat eggwhite in a small bowl until soft peaks form. Add extra 2 tablespoons of caster sugar, a little at a time, beating constantly until thick and glossy. Using a large metal spoon, fold eggwhites gently into the cream. Spoon meringue mixture over muffins. Dust with cocoa powder. Serve.
Notes & tips
To dissolve the coffee powder, mix it with the melted butter.
Muffins freeze well in snap-lock bags, but are best eaten on the day they are made.