Brush a sheet cake springform pan or the oven pan with butter and dust with flour. Preheat the oven to 175 ° C.
Beat the eggs with sugar and vanilla sugar until frothy. Add oil and water and keep stirring. Mix the flour with baking powder and salt and stir in slowly. Spread the dough on the prepared baking tray and bake for about 20 minutes. Let cool down.
Drain the pears (use the juice elsewhere) and place on the bottom. Beat the cream with the cream stiffener until stiff, stir in the sour cream, spread on the pears. Sprinkle with cinnamon sugar. Chill for at least two hours.