Preheat oven to 350 degrees F (175 degrees C); spray a 2 1/2-quart baking dish with cooking spray.
Heat the olive oil in a large skillet over medium heat; cook and stir the garlic, onion, and eggplant with the garlic until the vegetables have begun to soften, about 8 minutes. Stir in the zucchini, bell pepper, tomatoes, basil, parsley, salt, and black pepper; bring the mixture to a boil, stirring frequently. Reduce heat to medium-low and simmer until the vegetables are tender, about 20 minutes.
Cook the frozen ravioli as directed on the package; drain. Spread the cooked ravioli in a layer into the bottom of the prepared baking dish; spoon the hot vegetables over the ravioli. Sprinkle with the cheese.
Bake in the preheated oven until the casserole is bubbling and the cheese is melted, about 20 minutes.