Clean the rhubarb and cut into pieces. Mix with 100 grams of sugar and vanilla sugar. Let stand until the batter is ready.
For the dough, beat the eggs with soft butter and 300 grams of sugar until creamy. Mix together the flour, cornstarch, baking powder and salt. Add and mix everything until the dough comes off the edge of the bowl.
Line a 24-inch springform pan with baking paper. Then pour in the batter. Sieve the juice from the rhubarb and distribute the pieces on the dough. Dust the cinnamon over it.
Then in the oven, middle rail, upper u. Bake the bottom heat at 150 ° for approx. 75 minutes. Chopstick sample. When no more dough sticks to it, the cake is ready. 150 ° because the cake then bakes longer, but does not run the risk of turning black on top and has enough time to bake through.
Take the cake out of the oven and let it cool down. Remove the edge of the springform pan, dust the cake with powdered sugar and then enjoy your meal.