Peel and finely chop the onion. Heat oil in a pot, fry onion until transparent, add bay leaf and oregano, fry briefly. Stir in tomato paste, sauté briefly. Season with salt, pepper and paprika.
Deglaze with tomatoes and stock. Mash the tomatoes a little bit in the pot, bring to the boil and simmer at medium heat for about 15 minutes. Then season again with salt, pepper, paprika and sugar.
Meanwhile, prepare the pasta in boiling salted water according to the instructions on the packet. Pour into a sieve, quench briefly and drain. Arrange pasta and sauce on plates garnished with oregano and sprinkled with parmesan.