Bring a large pot of salted water to a boil. Cook the penne according to package directions until al dente (9–11 minutes). Reserve 1/4 cup of pasta water, then drain.

While pasta cooks, slice sausages in half lengthwise, then cut into bite-sized pieces.

In a skillet over medium heat, heat olive oil. Add sausage and cook until lightly browned, about 3 minutes. Scrape up any browned bits from the skillet.

Add butter and garlic; cook for 1 minute until garlic is fragrant.

Stir in marinara sauce and heavy cream. Simmer until heated through and well combined.

Add the drained pasta and toss to coat. Thin the sauce with reserved pasta water if needed.

Remove from heat and stir in grated Parmesan cheese to taste. Serve warm in bowls with bread on the side.