For the rum slices, first prepare the dough.
For the dough, cream butter, yolks and sugar until fluffy. Then stir in the remaining dry ingredients for the dough.
Beat egg whites until stiff and fold in. Put the dough on a baking tray with baking powder and bake at 170 degrees for about 20-30 minutes.
Mix the powdered sugar and rum for the glaze and spread on the cake while it is still warm. Allow the rum slices to cool before eating.