Melt the butter and leave to cool slightly.
Mix together the almonds, sugar and flour in a bowl. Add the egg whites, melted butter and chocolate, and mix until they are evenly combined.
Grease lightly a 12-hole muffin tin. Spoon the muffin mixture into the holes and arrange 3 cherries on top of each patty.
Bake in a preheated oven, 200°C (400°F), Gas Mark 6, for about 20 minutes until risen, golden and just firm in the centre. Leave in the tin for 10 minutes, then transfer to a wire rack to cool.
Dust lightly with icing sugar to serve.