Bring a large pot of salted water to a rolling boil. Add the rigatoni and cook until it’s al dente, which typically takes about 8–10 minutes. Drain and set aside.

In a large skillet or Dutch oven over medium heat, drizzle in the olive oil. Add the sliced kielbasa and sauté until browned and slightly crispy on the edges, about 5–7 minutes. Remove and set aside.

In the same pan, add the chopped yellow onion and bell peppers. Sauté for about 5–7 minutes until soft and fragrant.

Stir in the marinara sauce and 2 tablespoons of pesto. Allow it to simmer for a few minutes.

Add the cooked pasta and browned kielbasa back into the skillet. Sprinkle with Parmesan cheese and toss to coat evenly.

Transfer the mixture to a baking dish, drizzle with remaining pesto, and top with Italian cheese and remaining Parmesan.

Preheat your oven to 375°F and bake the dish for 20–25 minutes, or until the cheese is bubbly and golden.

Let the dish cool slightly before serving. Pair with a light salad or garlic bread.