Boil the spaghetti noodles in boiling water.
Cut the onion, garlic, and bacon into bite-sized pieces.
Heat olive oil in a pan and sauté the garlic, onion, and bacon.
Add the tomato sauce and bring to a boil.
Add the cooked noodles to the sauce and mix well.
Place the noodles and sauce into an oven-safe dish.
Top with mozzarella cheese.
Bake in a 180°C oven for 10–15 minutes.