Step 1

Heat 2 Tbsp. oil in a large skillet with a fitted lid over medium heat. Add onion and tomatoes; cook 7 to 8 minutes, until the onion is soft and tomatoes are broken down and jammy.

Step 2

Add pasta, marinara sauce, water, garlic powder, oregano, salt, and pepper. Increase heat to medium-high and bring mixture to a simmer. Cover and cook, stirring occasionally, until the pasta is al dente, 10 to 12 minutes.Remove lid and stir in heavy cream, spinach, and cheese. Stir continuously until spinach wilts and cheese melts, about 2 minutes. Garnish with fresh basil and Parmesan, if using.