Preheat the oven to 375 degrees F. Prepare a 2½ or 3 quart baking dish with a drizzle of the olive oil.
In a large saucepan over medium high heat, add the sausage and the fennel seeds to the pan and cook, stirring occasionally, about 5 minutes or until browned. Add the onion and cook until the onion is tender. Add the roasted red peppers and the marinara sauce and cook for 3-5 minutes or until warmed through.
Meanwhile, bring a large pot of water to a boil and generously season with kosher salt. Cook the rigatoni for 5 minutes. Add the rigatoni to the sauce and stir well to combine.
In a large bowl stir together the ricotta cheese, parmesan and parsley.
Layer half of the rigatoni and sauce in the baking dish. Dot half of the ricotta mixture over the pasta and layer 3-4 slices of provolone over the ricotta. Repeat with the remaining rigatoni and ricotta and top with 3-4 slices of provolone.
Bake uncovered for 20-25 minutes or until the cheese is bubbly and golden. Let cool for 5 minutes and serve.