Preheat oven 375°. Spray a sheet pan or baking sheet with cooking spray. Slice eggplant ¼” thick using a sharp chef's knife or a mandoline slicer (highly recommend using your mandoline slicer if you have).
Lay the eggplant on the baking sheet and bake for 10m. Let the eggplant cool for a few minutes before rolling.
In a medium bowl, add the ricotta cheese, mozzarella cheese, parmesan cheese, seasonings, and egg. Mix the ingredients together until full combined, the set aside.
Lay a slice of eggplant down on a cutting board or the sheet pan it baked in, then scoop 1-2 tablespoons of the ricotta mixture, then spread across the center of the eggplant.
Roll from the rounded edge to the cut side of the eggplant until you reach the end.
Pour a few tablespoons of marinara sauce into the bottom of a large baking dish, then lay the eggplant roll-ups seam side down into the baking dish.
Lastly, add a few spoonfuls of the tomato sauce atop each of the eggplant rolls, then sprinkle the remainder of the mozzarella cheese on top.
Place in the oven to bake for 20-25 minutes or until the cheese gets golden brown. Top the final dish with fresh rosemary or basil.
Notes
Pre-roll the eggplant after they bake. This will help them set and hold their shape as they cool, and when they roll with the ricotta on the inside.