Knead the flour with 75 g sugar, ground nuts and butter to make crumble.
Clean, peel and chop the rhubarb. Mix with 3 tablespoons of sugar and 1 tablespoon of cornstarch and place in a greased baking dish. Spread the sprinkles on top.
Bake in the preheated oven at 200 ° C for about 30 minutes. Sprinkle with chopped walnuts and serve.