Strain the sour cherries, let them drain and mix with 3 tablespoons of flour (the flour prevents the fruits from sinking too much). Mix the yolks with the sugar, vanilla sugar, cinnamon, lemon juice and zest until frothy. Slowly add the oil and then the water. Sieve the flour with baking powder and mix with the poppy seeds. Beat the egg whites with a pinch of salt to form firm snow. Pull the flour-poppy seed mixture and the snow under the yolk mass. Spread the dough on a greased and floured baking tray, spread the sour cherries on it and bake everything over medium heat for about 35 minutes. (180 ° C for stove without convection, 160 ° C with convection, middle rail). Slightly sugar-coated when cooled.