Instructions

In a 6-qt. stockpot, cook pasta according to package directions; drain and return to pot.
In a large skillet, heat half the butter and half the oil over medium-high heat. Saute half the shrimp with 1/4 teaspoon pepper flakes until shrimp turn pink, 3-5 minutes; remove from pan. Repeat with remaining butter, oil, shrimp and pepper flakes.
In same pan, heat marinara sauce and cream just to a boil over medium heat, stirring to blend. Stir in spinach until wilted; add to pasta. Stir in shrimp; heat through.