Prepare the Meatball Mixture: In a large mixing bowl, combine ground beef, minced onion, salt, pepper, garlic powder, onion powder, dried oregano, and crushed saltine crackers until well combined.

Form the Meatballs: Whisk eggs in a separate bowl and add to the meat mixture. Form into 2-inch meatballs and place them on a cookie sheet. Let rest for 20 minutes.

Sauté the Vegetables: Heat a skillet over medium heat. Add oil or butter, then sauté the diced green and red peppers and minced onions for 5-7 minutes until tender.

Brown the Meatballs: In the same skillet, cook the meatballs in batches for 8-10 minutes until browned. Transfer to a large soup pot.

Build the Sauce: In the soup pot, add sautéed vegetables, spaghetti sauce, water, and sugar. Stir to combine.

Simmer the Meatballs: Bring to a simmer over medium-low heat. Cover and simmer for 90 minutes, stirring occasionally.

Toast the Rolls: Preheat oven to 375°F (190°C). Slice rolls and toast for 5-7 minutes until golden.

Assemble Your Meatball Subs: Spoon sauce and meatballs into toasted rolls. Top with veggies and mozzarella balls. Add hot pepper rings if desired.