Step 1

Preheat the oven to 350°F.

Step 2

For the meat sauce: In a large Dutch oven, heat the oil over medium heat. Add the garlic, bell pepper, onion, and rosemary and cook until softened, 2 to 3 minutes. Add the sausage and chuck and cook, breaking the meat up with a wooden spoon, until browned, 6 to 7 minutes. Add the tomato paste and cook, stirring, until it turns a deep red, 3 to 5 minutes. Add the marinara sauce and stir to combine. Let cook on low to heat through.

Step 3

For the cheese layer: In a medium bowl, combine the cream cheese, cottage cheese, parmesan, basil, salt, and egg. Stir together well. Set aside.

Step 4

For the spaghetti layers: In a large bowl, toss the spaghetti with the pesto. Place half the spaghetti in an even layer in a 13-by-9-inch baking dish. Using a rubber spatula, spread the cheese mixture evenly over the pasta. Add the remaining spaghetti in an even layer. Top with the meat sauce, leaving a ½-inch border so you can see the spaghetti around the edges.

Step 5

Sprinkle the meat sauce with the mozzarella, cover loosely with foil, and bake for 20 minutes. Uncover and continue baking until bubbling and golden brown, 10 to 20 minutes. Let the spaghetti cool for 5 minutes. Top with basil and serve with crusty bread on the side.