Boil a large pot of salted water. Cook rigatoni according to package instructions. Reserve 1/2 cup of pasta water before draining.

In a large skillet, heat the olive oil over medium heat. Add the minced garlic and red pepper flakes, cooking for 1 minute until fragrant.

Add the chopped sun-dried tomatoes and heavy cream. Bring to a gentle simmer and let it thicken slightly for 3-4 minutes.

Stir in the grated parmesan cheese until the sauce is smooth and creamy. Add the fresh spinach and stir until wilted.

Toss the drained pasta into the skillet. If the sauce is too thick, add a splash of the reserved pasta water. Serve immediately with extra parmesan.