Sauce: Heat oil in large pot over medium heat. Add onions, garlic, carrots and peppers; cook, stirring, 10 to 12 minutes or until softened. Remove half for making meatballs.

Add tomatoes, sugar, salt and pepper flakes to vegetable mixture remaining in pot. Cover; bring to a boil. Reduce heat to medium; simmer, stirring occasionally, for 15 minutes.

Meatballs: Place reserved vegetable mixture, chuck, crumbs, zucchini, eggs, salt, Italian seasoning, pepper and Parmesan in large bowl. With clean, wet hands, mix.

Line baking sheet with waxed paper. Form meat mixture into 36 meatballs (1/4 scant cup for each). Place on prepared baking sheet.

Drop meatballs into simmering sauce; don't stir for 5 minutes. Simmer in sauce for another 30 minutes, gently stirring occasionally.

Spoon half of sauce and half the meatballs over cooked rotelli on large platter. Cool remaining sauce and meatballs for future Meatball Heros (recipe follows). Cover; refrigerate up to 3 days, or freeze up to 2 months. Makes 6 servings plus enough for Meatball Heros (recipe follows).

Meatball Heros: Thaw sauce and meatballs, if necessary, overnight in refrigerator. Gently heat in saucepan over low heat until warmed through. Meanwhile, cut 6 long buns in half and toast. Top 6 halves with 3 meatballs each plus sauce. If desired, sprinkle 8 ounces (total) shredded mozzarella cheese on top. Broil briefly to melt. Top with remaining bun halves.