Preheat oven at 350°F. Slice eggplant into 1/2 inch thick pieces. Grill until tender. Set aside.
Sauté onions in butter until tender. Transfer cooked onions in a bowl then add in 1/2 cup cheese, eggs, and hot sauce. Season with salt and pepper. Toss to mix. Arrange a layer of the eggplants in the bottom of an oven proof baking dish. Pour 1/3 of the egg mixture then make 2 more layers of eggplant and egg mixture ending with a layer of the eggplant slices.
Sprinkle remaining cheese and paprika. Bake for 30 minutes or until knife inserted comes out clean. Top with croutons before serving.