Preheat the oven to 180°
In a bowl, whisk together the butter and sugar until well combined.
Separate the egg yolks from the egg whites and add them to the batter. Then add the ground hazelnuts and mix until you get an even dough.
Add the sugar and baking powder, then de milk.
Now add the rum and the vanilla bean, then the flour.
When the batter is almost ready, whisk the egg whites in a separate bowl until firm.
Stir in the beaten egg whites and the dough is ready.
Pour the batter into the little tea cake pans and bake for 25 to 30 minutes.
Enjoy!!!!