Set ravioli on the counter.
Preheat the oven to 400 degrees F (200 degrees C). Spray a 9x13-inch baking pan with cooking spray. Spread 1 cup of marinara sauce into the bottom of the baking pan.
Spray a large skillet with cooking spray, and cook the Italian sausage over medium-high heat until browned, crumbling the meat as it cooks, about 5 minutes. Reduce heat to medium and drain grease.
Add remaining marinara sauce to the skillet. Add a little water to each jar and shake to get out the last of the sauce. Add to the skillet and bring sauce and meat to a simmer for 5 to 10 minutes. Remove from heat.
Place ravioli in a single layer in the prepared 9x13-inch pan, flat side down, overlapping if needed. Cover ravioli with 1 1/2 to 2 cups meat sauce and then 1/2 cup cheese. Repeat, adding another layer of ravioli, meat sauce, and cheese.
Top with remaining meat sauce and cheese and sprinkle Italian seasoning on top. Loosely cover with aluminum foil.
Bake, covered, in the preheated oven for 30 minutes. Uncover and bake until hot and bubbly, about 20 minutes more.
If desired, turn on the oven’s broiler, and broil to brown the topping, 2 to 3 minutes. Let stand for 10 minutes before serving.
