Mix flour with 1/4 teaspoon salt and dry yeast. Add butter in pieces and 200 g of sour cream and knead everything with the dough hooks of the hand mixer to a smooth dough. Cover and let it rest in a warm place for about 30 minutes.
Cook the pasta in boiling salted water according to the instructions on the packet. Drain and allow to drain. Cut the ham into cubes. Clean, wash and dice the peppers. Wash and clean the zucchini, also cut into cubes.
Peel and chop the onion. Drain the mushrooms, let them drip off and cut them in half. Mix 200 g sour cream, tomato sauce and cheese. Mix all ingredients, season with salt, pepper and herbs. Grease an ovenproof dish (25 x 30 cm) well and dust with flour.
Roll out approx. 2/3 of the dough on a floured work surface in a rectangular shape (approx. 35 x 40 cm) and line the mould with it. Spread the spaghetti filling over it. Roll out the rest of the dough also rectangular and cut into strips.
Spread strips in a grid pattern on the cake. Bake in the preheated oven (electric oven: 175 °C/ convection oven: 150 °C/ gas: level 2) on the lower rack for 40-50 minutes. Before cutting (best with an electric knife) let rest for about 10 minutes.
A green salad tastes good with it.