Knead the dough ingredients, wrap in foil and refrigerate for 30 minutes. Line a greased springform pan (26 cm diameter) with the dough, pull up a small edge. Mix the breadcrumbs and sugar and sprinkle them on the dough.
Briefly blanch the rhubarb, drain well and spread on the dough.
Then prebake in an oven preheated to 190 degrees for about 20 minutes. Take the cake out of the oven and sprinkle with 75 g of sugar.
Mix egg yolks with sour cream, sugar and starch, possibly stir in 1 - 2 tablespoons of liqueur. Beat egg whites until stiff and fold in. Spread on the pre-baked cake and bake for another 15 minutes at the same temperature.
Tip:
The cake should really be eaten on the baking day because it becomes soggy very quickly.