Cook Ravioli According To Package Directions. Meanwhile, In A Large Saucepan, Saute Mushrooms, Pepperoni And Onion In Butter Until Onion Is Tender. Stir In Tomato Sauce, Parmesan Cheese, Garlic Powder, Basil, Oregano And Cayenne; Heat Through. Remove From The Heat; Stir In Sour Cream. Drain Ravioli; Toss With Cream Sauce.