Boil eggs hard for 10 minutes. Peel and finely dice onions. Fry 1/3 of the onion cubes in 2 tablespoons of hot oil until transparent. Add tomatoes with juice and let it boil down a bit in an open pot.
Season with salt, pepper and sugar. Drain eggs and rinse with cold water. Sort and wash the spinach. Drain well. Peel and chop the garlic. Fry the remaining onion cubes and garlic in the remaining oil.
Add the spinach and let it collapse. Season strongly with salt and pepper. Drain the spinach well. Chop the eggs and add to the spinach. Stir in crème fraiche. Fill cannelloni rolls with spinach egg mixture and layer in a flat casserole dish.
Pour tomato sauce over individual layers. Pour the rest of the tomato sauce over the cannelloni at the end. Grate the cheese and sprinkle over the cannelloni. Bake in the preheated oven (electric cooker: 200 °C/ gas: level 3) for about 35 minutes.