Preheat your oven to 375℉. Prep a baking tray with nonstick cooking spray or a silicone mat and set aside.
Wash and slice your eggplant into thin strips using a mandolin slicer or a sharp knife to cut them into 1/4" slices. Lightly salt each slice and let it sweat for a few minutes to reduce the moisture content. Wipe them off, place them on the baking sheet, and bake for 10 minutes.
Heat the olive oil in a medium skillet over medium-high heat. Saute the onion for several minutes until translucent. Add the garlic and saute for another minute.
Add the tomatoes, Italian seasoning, chopped basil, and salt and pepper to taste. Simmer for five minutes to combine the flavors.
Meanwhile, mix together the parmesan, mozzarella, and ricotta with the onion powder, garlic powder, chopped spinach, and salt and pepper.
Spoon a couple of tablespoons of cheese mixture onto each baked eggplant slice. Roll into a roll-up shape and place in a small baking dish. Repeat with all eggplant slices. Top with the tomato sauce and some extra cheese.
Cover and bake for 20-25 minutes until bubbly. Remove the foil and let the cheese brown for 8-10 minutes. Top with extra fresh basil if desired, and serve warm. Store leftovers in the fridge in an airtight container for 3-4 days.