Prepare all ingredients:
Crush the nuts...
...and brown them in a dry pan.
Work the softened butter and the icing sugar using a whisk.
Add the egg yolks one at a time...
...then the flour with baking powder...
...then the cooled hazelnuts.
Beat the egg whites firm...
... and add them to the mixture.
Mold in a silicone mini-loaf mold.
Bake in preheated oven (200°C - th. 7) for about 15 to 20 minutes.
Wait for a few seconds before removing from the mold.