Preheat oven to 350 F. Option to line 2 rimmed baking sheets with parchment paper for easy clean up. Cut off the eggplant stem and slice lengthwise into 1/4" steaks. (Option to peel before slicing, although not necessary.)
Place eggplant on prepared baking sheets and spray with cooking spray (or brush with oil) on both sides. Bake in preheated oven for 15-20 minutes, until softened. This releases excess moisture and makes the eggplant easier to roll.
In a bowl, combine the ricotta, shredded mozzarella, grated Parmesan, egg, garlic, chopped basil, salt, and pepper. Mix until well combined.
Spread a spoonful of the filling onto each cooled eggplant slice. Roll them up and place them seam-side down in a 9x13" baking dish. Pour marinara sauce over the rolled eggplant. Sprinkle additional shredded mozzarella on top.
Bake in the oven for 25-30 minutes or until the cheese is bubbly and golden.
Garnish with fresh basil or parsley if desired. Serve the Eggplant Rollatini hot and enjoy!