Place your oven rack 5 inches from the heat. Preheat your oven's broiler. Line a large baking sheet with foil and spray with nonstick spray. Arrange the eggplant slices on the baking sheet. Broil, without turning, until deep golden brown, about 6 minutes. Remove from the oven and let cool.
Preheat the oven to 375 degrees F. Spray a 9x13 inch (or slightly smaller) dish with nonstick spray.
In a large nonstick skillet, heat the olive oil and add the onion and garlic. Cook, stirring occasionally, about 5 minutes.
In a medium bowl, stir together the ricotta, parsley, and oregano. Stir in the onion mixture. Spread a couple of teaspoonfuls of the ricotta mixture onto the pale side of each eggplant slice. Spread to cover. Roll up each slice to enclose the filling.
Place the eggplant rolls, seam-side-down, in the prepared baking dish. Spoon the marinara sauce on top of the rolls. Sprinkle with shredded cheese and Parmesan.
Bake until the eggplant is browned and the sauce is bubbly, about 30 minutes. Serve immediately.
