Preheat oven to 200°C ( 392°F)
Sift the flour and cocoa into a mixing bowl.
Melt chocolate and butter over low heat, stirring occasionally.
Remove from the heat, add the sugar and stir.
Stir in flour, milk and eggs. Mix roughly with a spoon. Do not overwork. The batter should look lumpy.
Transfer the batter into a piping bag and fill the muffin cups liners three-quarters full.
Bake in the oven for 20 to 25 minutes, depending on your oven. A skewer pricked in the center should come out dry.
Leave to cool and decorate the top with Swiss chocolate meringue buttercream a very light buttercream.