Bring a large pot of salted water to a boil. Add the spaghetti noodles and cook according to the package instructions (usually 8–10 minutes) until al dente. Drain and set aside.

In a medium saucepan, heat the olive oil over medium heat. Sauté the garlic and onions for about 2–3 minutes until they become fragrant and translucent.

Mix in the crushed tomatoes, tomato paste, sugar, oregano, basil, salt, pepper, and chili flakes (if using). Stir well and let this sauce simmer uncovered for 10–15 minutes, stirring occasionally.

While the sauce is simmering, prepare the mozzarella eyeballs by pressing half a black olive into the center of each mozzarella ball. Optionally, add a drop of balsamic glaze or black food coloring in the middle.

Toss the cooked spaghetti into the bloody sauce, ensuring each strand is well coated.

Plate the spaghetti and place the mozzarella eyeballs on top, nestling them into the noodles.

For additional Halloween flair, consider serving with garlic 'fingers' or crusty bread.