Melt the chocolate and butter, both cut into pieces, in a double boiler.

Mix the eggs and sugar in a bowl with a whisk.

If you have a planetary mixer, run it at medium speed with eggs and sugar.

Continue with the whisk for 2 minutes.

Add the sifted flour to the eggs.

Mix the melted butter and chocolate in such a way as to obtain a single and smooth mixture.

Add the chocolate and butter mixture to the eggs.

Continue with the whisk for at least another 3 minutes.

The dough will be firmer after this step.

Based on the density of the dough, decide whether to put the mixture in a pastry bag or use a ladle to dress the cups.

The density of the dough depends very much on the temperature of the environment and on the working time with the whisk in the last step.

Grease and sweeten (with icing sugar) all sides of the aluminum cups.

Place the dough in buttered and sweetened cups.

Gently beat the bottom of the cup on the work surface to let the air escape and make sure that the dough fills all the spaces in the cup.

Bake in a preheated oven at 180 ° C for 7/9 minutes.