For the first dough separate 5 eggs.
Mix egg yolks with sugar and oil until foamy. Mix wholemeal spelt flour with a little baking soda and mix in.
For the second dough, separate the remaining 2 eggs. Mix egg yolks with sugar, vanilla sugar and lemon zest until foamy. Mix in curd cheese, potato starch and rum. Beat all 7 egg whites with a little lemon juice until stiff. Gently fold the snow mixture into the 2 doughs, depending on the amount of egg.
Spread the first batter into a greased and floured cake pan, then spread the curd batter on top. Bake in the oven at medium heat.