Start by bringing a large pot of salted water to a boil. Add the penne pasta and cook according to package instructions until al dente, usually about 10 minutes. Drain the pasta and set it aside. Don’t rinse — you want the pasta to hold onto the sauce later.
In a large skillet, heat 2 tablespoons of olive oil over medium heat. Add the turkey sausage (with casings removed) and cook, breaking it up with a spoon, until browned and cooked through, about 6-8 minutes. Toss in the minced garlic and sauté for another 1-2 minutes until fragrant.
Now, add the chopped broccoli rabe to the skillet. Stir it in with the sausage and garlic, letting it cook down until tender, about 4-5 minutes. Sprinkle in the red pepper flakes, salt, and pepper to taste, mixing well to combine the flavors.
Remove the skillet from heat. Gently fold in the cooked penne pasta, ricotta cheese, and half of the shredded mozzarella cheese. Stir just until everything is evenly combined — the ricotta will add a creamy texture that envelops the pasta and sausage mixture.
Transfer the mixture into your 9x13-inch baking dish, spreading it out evenly. Sprinkle the remaining mozzarella and the grated Parmesan cheese evenly on top. This cheese layer will form a golden, bubbly crust as it bakes.
Preheat your oven to 375°F (190°C). Bake the pasta bake uncovered for 20-25 minutes or until the cheese on top is melted and golden brown. If you want an extra bubbly top, you can broil for the last 2-3 minutes—just watch carefully to avoid burning.
Once out of the oven, let the pasta bake cool for 5 minutes to set. Garnish with fresh basil leaves for a pop of color and fresh herbaceous flavor. Serve warm and enjoy!