For the rhubarb cake with icing, make a shortcrust pastry and let it rest for 30 minutes. Then spread it in a cake pan and raise the edge about 2 cm, spread some breadcrumbs on it and spread the rhubarb pieces.
Bake at 180°C convection oven for 20-30 minutes.
During this time, prepare the glaze: Beat egg whites, continue beating with a little sugar and whisk remaining sugar with egg yolks until fluffy. Gently stir sour cream into the fluffy mixture and fold in egg white whites. Voilà – pour onto the cake (will be quite high) and finish baking over about 15-25 minutes.
After that, let it cool in the mold and only then put it on the cake plate. Sprinkle the rhubarb cake with icing with vanilla powdered sugar – ready!