01 - Preheat oven to 400°F. Lightly grease a 9x13 inch baking dish.
02 - Combine all meatball ingredients in a large bowl. Mix gently until just combined. Shape into 24 small meatballs, approximately 1 tablespoon each.
03 - Heat olive oil in a large skillet over medium-high heat. Brown meatballs on all sides for about 5 minutes. They need not be cooked through. Transfer to a plate.
04 - Boil pasta in salted water for 2 minutes less than package directions. Drain well.
05 - Combine partially cooked pasta, marinara sauce, and water in the prepared baking dish. Stir thoroughly to coat pasta evenly.
06 - Distribute browned meatballs evenly throughout the pasta. Sprinkle mozzarella and Parmesan cheese over the surface.
07 - Cover tightly with aluminum foil. Bake for 25 minutes.
08 - Remove foil and continue baking for 15 to 20 minutes until cheese turns golden and sauce bubbles actively.
09 - Let casserole rest for 10 minutes before serving. Scatter torn basil leaves across the top.