01 - Preheat oven to 375°F. Grease a 9-inch pie dish or deep baking dish with cooking spray or butter.
02 - Bring a large pot of salted water to a boil. Cook spaghetti until just al dente, then drain and set aside.
03 - While the pasta cooks, heat a large skillet over medium heat. Add the ground Italian sausage, breaking it apart with a wooden spoon, and cook until fully browned. Drain off any excess fat.
04 - Add the diced onion, chopped bell pepper, minced garlic, and seeded jalapeños to the skillet with the sausage. Sauté for 4 to 5 minutes until the vegetables are softened and fragrant.
05 - Stir in the marinara sauce, tomato paste, crushed red pepper flakes, dried oregano, and smoked paprika. Season with salt and black pepper to taste. Let the sauce simmer for 5 minutes to meld the flavors.
06 - In a large mixing bowl, combine the cooked spaghetti, ricotta cheese, beaten eggs, and chopped fresh basil. Toss until the pasta is evenly coated throughout.
07 - Spread the spaghetti mixture into the prepared pie dish, pressing it evenly across the bottom and up the sides to form a crust layer.
08 - Spoon the sausage and vegetable sauce over the spaghetti base, spreading it in an even layer. Sprinkle the shredded mozzarella and grated Parmesan evenly over the top.
09 - Bake for 25 to 30 minutes, or until the cheese is fully melted and golden brown on top. Remove from the oven and let the pie cool for 10 minutes before slicing.
10 - Garnish with additional fresh basil leaves and serve warm.