Melt the chocolate over a pan of hot water, set aside to cool down.
If you are using silicone cupcake forms, you don’t have to prepare them, otherwise grease them and sprinkle with sugar.
Preheat and oven to 180C (160C for fan ovens).
Beat the butter with approx. half of the sugar for a few minutes until the mixture gets fluffy; one by one add the egg yolks and then the cool chocolate, beat till everything is combined.
Whisk the egg whites till stiff, add the rest of the sugar and whisk for 2 minutes longer.
Add the third of the whisked egg whites and third of the ground almonds to the bowl with chocolate mixture, gently stir with a spatula. Repeat the process twice till you have used the egg whites and almonds.
Divide the batter between 12 cupcake forms and put to the hot oven for 25-30 minutes until a wooden stick inserted to a cupcake comes out clean.
Dust with icing sugar, or – if you prefer them to be sweeter – pour melted chocolate on top.
The recipe comes from a Polish cookbook “Ciasteczka – wyszukane smakołyki z całego świata”