Grease a 13 x 9" or other 3-quart baking dish with 1 T. oil. Spread 1 c. tomato sauce in bottom of dish.
Arrange half of ravioli over sauce in baking dish in a single layer, slightly overlapping ravioli. Spread 1 c. tomato sauce evenly over ravioli. Sprinkle with half of cheese. Repeat layers once, using remaining ravioli, tomato sauce, and cheese. Bake until sauce is bubbly and cheese is melted and golden, 30 to 35 minutes.
Adapted from Real Simple magazine, May 2021, p. 128.