Put the quark through a sieve, stir with milk, oil, egg and salt until smooth. Mix in half of the flour mixed with the baking powder, then add the rest of the flour, work everything into a smooth dough. Roll out the dough, cover a greased baking sheet with it, press up one edge all around.
Briefly sauté the bacon and onions, leave to cool and place on the pastry plate. Mix the eggs with the cream, salt and caraway seeds and pour over the bacon onions. Bake the onion cake for 20-25 minutes at 210-220 degrees, cut into pieces while still hot and serve.