Prepare pizza dough and tomato sauce. In the meantime, sort out the spinach, wash and drain. Peel and chop the onion. Heat 1 tablespoon of oil in a saucepan. Fry the onion in it. Add the spinach and let it collapse open.
Season with salt and pepper.
Finely grate the parmesan. Mix spinach, sour cream and parmesan. Press the sausage meat from the skin into the tomato sauce and mix. Preheat oven (electric cooker: 225°C/circulating air: 200°C/gas: level 4).
Coat the depressions of a muffin tray (12 depressions) with oil and sprinkle with 4 tablespoons of breadcrumbs. Roll out the pizza dough rectangularly (approx. 39x52 cm), cut into 12 squares of the same size and place them in the recesses.
Sprinkle the dough bases thinly with the remaining breadcrumbs.
Mix the tomato sauce with the spinach mix and spread into the muffin wells. Beat the protruding dough corners over the filling. Bake muffins in a hot oven for 15-20 minutes. Allow to cool slightly, then remove from the muffin wells and serve immediately.