Adjust rack to top position and preheat oven to 425 degrees. Bring a large pot of salted water to a boil.

In a small bowl, combine panko, mozzarella, and a large drizzle of olive oil; season with salt and pepper.

In a large bowl, combine pork*, half the panko mixture, half the Tuscan Heat Spice (you’ll use the rest later), and 1 TBSP water (2 TBSP for 4 servings); season generously with salt (we used ½ tsp; 1 tsp for 4) and pepper.

Form pork mixture into two 1-inch-tall loaves (four loaves for 4); flatten tops. Place on a lightly oiled baking sheet.

Swap in beef* for pork. 

Evenly spread tops of meatloaves with 1 TBSP marinara each (you’ll use the rest later). Mound with remaining panko mixture, pressing gently to adhere.

Bake meatloaves on top rack until pork is cooked through and crust is browned and crispy, 22-28 minutes.

Once water is boiling, add spaghetti to pot. Cook, stirring occasionally, until al dente, 9-11 minutes.

Reserve ¾ cup pasta cooking water (1½ cups for 4 servings), then drain.

Heat pot used for pasta over medium-high heat. Add reserved pasta cooking water, tomato paste, stock concentrates, remaining marinara, remaining Tuscan Heat Spice, 2 tsp olive oil, ½ tsp salt, and 1½ tsp sugar (4 tsp olive oil, 1 tsp salt, and 3 tsp sugar for 4 servings).

Bring to a boil, then reduce to a simmer. Cook until slightly thickened, 3-5 minutes.

Stir drained spaghetti, half the Parmesan, and 1 TBSP butter (2 TBSP for 4 servings) into pot with sauce. Season generously with salt and pepper.

Divide pasta between plates or shallow bowls and top with meatloaves. (TIP: If you prefer, serve meatloaves on the side instead.) Sprinkle with remaining Parmesan and serve.