Eggplant Ricotta Bake

INGREDIENTS

• 2 large eggplants (1 to 1 1/4 pounds each), sliced lengthwise 3/4 inch thick
• 3 tablespoons olive oil, plus more for baking dish
• Coarse salt and ground pepper
• 1 container (15 ounces) part-skim ricotta cheese (1 2/3 cups)
• 3 large eggs
• 1 cup grated Parmesan cheese
• 2 tablespoons chopped fresh oregano (or 2 teaspoons dried)
• 1 jar (16 ounces) store-bought marinara sauce (2 cups)