01 - Preheat oven to 375°F. Lightly grease a 9x13 inch baking dish.
02 - Bring a large pot of salted water to a boil. Cook pasta until just al dente, about 1–2 minutes less than package directions. Drain and set aside.
03 - Heat olive oil in a large skillet over medium heat. Add onion and cook until translucent, about 4 minutes. Add garlic and red bell pepper; sauté for 2 minutes.
04 - Add plant-based sausage crumbles to skillet and cook until lightly browned, approximately 4 minutes.
05 - Stir in crushed tomatoes, tomato sauce, Italian herbs, dried basil, red pepper flakes, salt, and black pepper. Simmer for 10 minutes, stirring occasionally.
06 - In a large bowl, combine cooked pasta, half of the mozzarella, half of the Parmesan, all ricotta, and half of the sauce. Gently mix to combine.
07 - Spread half of the pasta mixture evenly in the prepared baking dish. Top with remaining sauce, then sprinkle with remaining mozzarella and Parmesan cheese.
08 - Cover dish with foil and bake for 20 minutes. Remove foil and bake an additional 10 to 15 minutes until cheese is bubbly and golden.
09 - Allow to rest for 10 minutes before serving. Garnish with fresh basil leaves.