Wash, clean and dice the tomatoes. Prepare pasta in boiling salted water according to package instructions. Peel garlic and press it through a garlic press. Pluck Parma ham a little smaller.
Wash lemon hot, grate dry and grate peel. Halve the lemon and squeeze one half. Wash basil, dab dry and cut leaves, except for some for garnishing, from the stems and cut into strips.
Mix tomatoes, garlic, ham, lemon juice and zest, basil and oil. Season to taste with sugar, salt and pepper. Drain mozzarella and cut into cubes. Drain the pasta (do not rinse) and immediately put it back into the still hot pot.
Fold in the tomato mixture and arrange on plates. Sprinkle with mozzarella and garnish with basil leaves.