A delightful Italian-inspired pasta casserole with a rich and zesty flavor.
Cook the penne pasta in a large pot of boiling salted water until al dente. Drain and set aside.
Do not overcook the pasta as it will continue to cook in the oven.
Heat the olive oil in a large skillet over medium heat. Add the onion and garlic, and sauté until softened.
Stir frequently to prevent the garlic from burning.
Add the sausage to the skillet and cook until browned and fully cooked. Remove excess fat if necessary.
Break the sausage into small pieces as it cooks for even browning.
Stir in the tomato sauce, basil, and red pepper flakes. Simmer for 10 minutes to allow the flavors to meld.
Taste and adjust seasoning with salt and pepper if needed.
Preheat the oven to 350°F (175°C). Grease a casserole dish with a bit of olive oil.
Ensure the dish is evenly greased to prevent sticking.
Layer half of the pasta in the casserole dish, followed by half of the sauce, half of the zucchini slices, and half of the cheese. Repeat the layers.
Press down gently on each layer to compact the casserole.
Cover the dish with foil and bake for 30 minutes. Remove the foil and bake for an additional 10 minutes until the cheese is bubbly and golden.
Let the casserole rest for 5 minutes before serving to set the layers.
Serve the casserole hot, garnished with fresh basil if desired.
Pair with a side salad or garlic bread for a complete meal.