PREHEAT oven to 350° F. Spray 13 x 9-inch baking dish with nonstick cooking spray.
PREPARE pasta according to package directions.
HEAT oil in a large skillet over medium-high heat. Add eggplant; cook, stirring occasionally, for 6 to 8 minutes or until slightly tender. Add marinara sauce; stir to combine. Remove from heat.
ARRANGE half of the raviolis in the bottom of prepared baking dish. Pour half of the eggplant mixture over raviolis. Dollop the ricotta cheese evenly. Arrange remaining raviolis on top. Pour remaining eggplant mixture over raviolis; sprinkle Parmesan cheese evenly over the top.
BAKE for 15 to 20 minutes. Preheat broiler; broil for 2 minutes until Parmesan cheese is golden brown. Garnish with fresh oregano, if desired.