For the dough, mix all the ingredients and beat the egg whites with a pinch of salt until very stiff and fold into the dough, pour the dough into a springform pan 26 cm and bake at 180 ° C for about 50 minutes.
Then turn the cake out of the mold and let it cool. For the filling, mix the ingredients until smooth and cut the cake 1x or 2x depending on your preference and fill with the mascarpone cream.
Save some filling to cover the outside of the cake with it and then decorate with walnut halves.