For the dough base, mix the flour and baking powder and sieve. Add the sugar and vanilla sugar, as well as the egg and margarine. Process everything into a dough with a hand mixer (kneading). Grease a springform pan (26 diameter) and shape 2/3 of the dough into a ball, which then roll out on the springform pan. Shape the rest of the dough into a roll and then place it on the edge of the springform pan and form a 3 cm wide edge.
For the filling, loosen up the quark in a mixing bowl. Then separate the eggs from each other. Add all ingredients (except for the egg white!) Slowly and one after the other to the quark and stir slowly with a spatula. Beat egg whites until stiff and fold in. Then pour the whole mixture into the prepared form and smooth it out. Bake on the wire rack at 160 ° (gas level 3) for about 1 1/2 hours. The oven should not be opened within the baking time !!!
After the baking time, turn off the oven and let the cake cool for approx. 1 hour with the door open. Then loosen the ring shape and decorate as you wish! Good Appetite!!!