Before starting, preheat the oven to 450˚F. Wash and dry all produce. Add 10 cups water and 2 tsp salt to a large pot (use same for 4 ppl). Cover and bring to a boil over high heat. Add penne to the boiling water. Cook uncovered, stirring occasionally, until tender, 10-12 min. Reserve 1/2 cup pasta water (dbl for 4 ppl), then drain and return penne to the same pot, off heat.

Meanwhile, add beef, breadcrumbs, half the soy sauce, half the garlic powder, 2 tbsp milk, 3 tbsp Parmesan and 1/4 tsp salt (dbl all for 4 ppl) to a large bowl. Season with pepper, then combine. Roll mixture into 8 equal-sized meatballs (16 for 4 ppl). Transfer meatballs to an 8x8-inch baking dish (9x13-inch for 4 ppl).Roast in the top of the oven until cooked through, 10-12 min.**When meatballs are done, switch the oven to broil.

Meanwhile, heat a large non-stick pan over medium heat. Add tomato sauce base, marinara sauce, remaining garlic powder, remaining soy sauce and 1/2 tsp sugar (dbl for 4 ppl). Season with salt and pepper. Bring to a gentle simmer, stirring occasionally. Simmer, stirring occasionally, until sauce thickens slightly, 2-3 min. Add 1 tbsp butter (dbl for 4 ppl), then stir until melted.

Add penne and reserved pasta water to the pan with sauce. Increase heat to medium-high. Cook, stirring occasionally, until sauce thickens and coats penne, 2-3 min. Meanwhile, roughly chop spinach. Add spinach. Cook, stirring constantly, until spinach wilts, 1 min. Season with salt and pepper, to taste.

Add meatballs to the pan with penne, then gently toss to coat meatballs in sauce. Transfer penne and meatballs to the baking dish used for meatballs. Sprinkle mozzarella, then remaining Parmesan over top. Broil penne and meatballs in the middle of the oven until cheese is melted and top is golden, 4-6 min. (TIP: Keep your eye on penne and meatballs so they don't burn!)

Divide penne and meatballs between plates.