Preheat oven to 450°F and lightly coat 2 sheet pans with olive oil spray.

Slice eggplant into 1/4-inch thick pieces and arrange on pans, allowing for slight overlaps, if necessary. Season with salt and bake 20 minutes, flipping slices halfway through, until golden brown.

In medium bowl, combine ricotta, egg, parsley, and 1/4 cup Romano cheese.

Reduce oven temperature to 400°F. Spread 1/2 cup sauce on bottom of 13x9-inch baking dish. Then layer 1/3 eggplant on bottom, 1/3 ricotta mixture, 3/4 cup mozzarella, and 3/4 cup sauce. Repeat layers two more times with 1/3 eggplant, 1/3 ricotta, 3/4 cup mozzarella, and sauce. Reserve mozzarella for final layer.

Finish by covering casserole with remaining sauce, mozzarella, and grated cheese.

Cover with foil and bake 40 minutes until cheese melts and casserole is bubbling. Remove foil and bake additional 10 minutes. Let stand 10 minutes before slicing.