Spray a 9x13-inch baking dish with cooking spray and preheat the oven to 375 F.
Make the sauce: melt the butter in a large skillet over medium heat and saute the garlic for 30 seconds. Sprinkle in the flour and cook for 1 minute or until bubbly and golden. Whisk in the milk and simmer until thickened about 1 minute. Stir in the spinach, artichoke hearts, cream cheese, Parmesan cheese, ⅔ cup shredded mozzarella, oregano, basil, red pepper flakes, salt, and pepper, and cook until the cheese has melted about 2-3 minutes.
Assemble the dish: spread a thin layer of sauce into the bottom of the baking dish. Lay the ravioli in a single layer over the sauce, and spread half of the remaining sauce over the ravioli. Add a second layer of ravioli, top with the remaining sauce, and sprinkle the remaining ⅓ cup mozzarella on top. Bake for 30 minutes or until the cheese is melted and golden.
