Beat the eggs with the sugar until creamy. Gradually add the flour mixed with the baking powder. Stir in the peeled apples, freed from the core and cut into small cubes. Season with cinnamon and lemon zest. Pour the mixture into a buttered springform pan and bake in a heated oven at 180 °C for about 30 to 35 minutes. After cooling, dust with powdered sugar. This juicy pastry is well suited for sweet or sour apples on the spot.