In a medium bowl, combine all the ingredients for the meatballs and gently mix until all is combined. Cover and refrigerate the mixture for at least 30 minutes.
Meanwhile, to make the marinara sauce, add the olive oil to a large stainless-steel pot or Dutch oven over medium heat. When the oil is hot, add the sliced garlic. Cook until the garlic becomes soft, slightly translucent, and very fragrant. Remove the garlic from the pot.
Add both cans of tomatoes, the Italian seasoning, dried basil, red chili flakes, salt, and ground black pepper and stir. Reduce the heat to low, place a lid on the pot, and simmer for 25 to 30 minutes. Taste the sauce. If it is too acidic, add ½ tablespoon of sugar. Taste it again, and add the remaining sugar if necessary.
While the sauce is simmering, return to the meatballs: Preheat the oven to 425°F, line a rimmed baking sheet with foil, and spray the foil with non-stick spray.
Remove the meat mixture from the refrigerator. Form the mixture into 1½-inch balls and place them on a baking sheet. Bake the meatballs for 10 to 15 minutes, or until they are browned and cooked through.
While the meatballs are cooking, prepare the spaghetti according to the package directions.
To serve, add the desired amount of pasta to a plate, spoon over the sauce, and top with meatballs. Sprinkle with grated Parmesan cheese and chopped parsley.