Spread base with shortcrust pastry and bake. After cooling, put in edge of shortcrust pastry. Sprinkle in some breadcrumbs.
Pour in the cooked cream frosting and put in the rhubarb pieces. From the rest of the shortcrust pastry, pressed through a coarse sieve, sprinkle crumble.
Bake at 200 °C for about 50 minutes. Dust lightly with powdered sugar.