Whisk butter and sugar until white and puffy. Stir down the vanilla powder and one egg at the time. Then add flour and baking powder. Pour the batter in a buttered and breaded round spring form.

Bake in 200ºC for 18-20 minutes.

The cake should be a little wet in the middle when done. Let cool (until next day is nice).  Serve with whipped cream and fresh berries.