Beat the ten egg whites, which are at room temperature, with baking powder, salt and the pulp of the vanilla pod to form egg whites. Then stir in 125 g of the sugar.
Mix the rice flour, millet flour, corn flour, potato flour and the remaining sugar in a separate bowl and add the flour mixture to the egg whites.
Put the dough in a greased springform pan with a diameter of approx. 24-26 cm or lined with baking paper and bake on the middle shelf for 45 minutes at top / bottom heat.
Puree the frozen berries and sweeten with a sweetener of your choice.
After cooling, dust the cake with powdered sugar and serve with fruit puree.