Heat the oven to 180ºC. Grease and base line a 22cm round cake tin.
Sift the baking flour, potato flour and baking powder together in a separate bowl.
Beat together the butter and sugar in another mixing bowl until light. Beat in the egg yolks one at a time, stirring well until creamy.
Gradually add the dry ingredients with the egg yolk mixture, until well mixed.
Beat the egg whites with a pinch of salt until stiff and carefully fold into the egg yolk mixture.
Bake for about 30 minutes until risen and golden brown. Let it cool. Remove from the tin and cut into 2 or 3 layers horizontally. Brush the layers with a little milk.
To make the filling, mix together the cream cheese and the icing sugar. Fold in the whipped cream or half cup condensed milk. Use half the filling to spread into the layer.
Put the layers together. Spread the remaining filling over the top and sides of the cake. Decorate your cake with your own decoration.
