Preheat oven to 450°.
Spread 1/2 cup pasta sauce in bottom of an 8-inch square baking dish coated with cooking spray. Arrange 2 noodles over sauce; top with half of artichokes, half of bell peppers, 1/4 cup pepperoni, and half of olives. Sprinkle with 1/2 cup cheese; top with 3/4 cup sauce. Repeat layers, omitting cheese, ending with noodles. Spread remaining sauce over noodles. Cover and bake at 450° for 30 minutes or until noodles are tender and sauce is bubbly. Uncover and top with 1/2 cup cheese; bake an additional 5 minutes. Let stand 5 minutes. Garnish with oregano sprigs, if desired.