Preheat oven to 375 degrees. Coat a 9 x 9-inch baking dish with cooking spray. Set aside.
Cook ravioli according to package instructions. Drain and rinse in cold water. Set aside. If it sticks together, you might need to rinse it again in cold water before adding to the cheese sauce.
To make the cheese sauce: In a large nonstick pot melt butter. mix in dry mustard powder and cayenne pepper. Using a rubber spatula, mix in milk, cottage cheese, 1 cup mozzarella cheese, and feta cheese. Season with a little, garlic salt or garlic powder and a little salt, if using powder.
Using the rubber spatula so ravioli doesn’t tear, stir in cooked ravioli and tomatoes. Mix well. Add to baking dish and spread evenly. Sprinkle with ¼ cup shredded mozzarella cheese and the Parmesan cheese all over top of casserole. Bake in oven for about 15 minutes, until golden and the cheeses are melted.
Cool slightly and cut into 6 servings. This casserole freezes great!