For the dough, beat the fat and sugar until frothy, stir in the egg. Mix flour and baking powder and add. Use the dough hook of the hand mixer to make crumbles. Press 2/3 of the crumbles firmly onto a greased deep baking tray.
Finely grind the poppy seeds. Boil up with 1/2 litre milk, sugar, lemon peel and fat and let it swell for about 10 minutes. Separate the eggs. Whisk egg yolk, remaining milk and starch, add to the poppy seed, bring to the boil again briefly, then let cool off lukewarm.
Beat the egg whites until stiff, pour in the cinnamon. Fold into the poppy seed mixture and spread on the crumbles. Separate the eggs for the quark layer. Mix quark, oil, sugar, egg yolk, starch and lemon juice until smooth.
Beat the egg white until stiff and fold in. Spread the mixture over the poppy seed layer. Sprinkle with remaining crumbles. Bake in the preheated oven (electric: 175 °C/ gas: level 2) for approx. 50 minutes. Results in about 30 pieces.
Serve dusted with icing sugar.