Preheat the oven to 350°F (175°C).
Drain the soaked cashews and place them in a blender or food processor with the garlic, nutritional yeast, lemon juice and almond milk. Blend until the cashews have broken down into a creamy consistency. Add in the spinach and basil and continue to blend until completely smooth. Season with salt and pepper and set aside (this can be made up to a day in advance).
Cut the baby eggplant lengthwise into ¼ to ½ inch thick slices. Lightly salt each side and allow to rest for 10-15 minutes to remove excess moisture. After 15 minutes wipe the eggplant with paper towels to remove the salt.
The baby eggplant can be grilled for 2-3 minutes per side on a well-oiled grill or baked in the oven for 15 minutes at 350°F (175°C). Once cooked remove and set aside.
To make the sauce, heat the olive oil in a pot on medium low heat and add the garlic, do not allow to brown. Cook until soft before adding in the chopped tomatoes and sweetener, if using. Let the sauce simmer for 10 minutes until it begins to thicken. Puree sauce to a smoother consistency but still slightly chunky. Season with salt and pepper and pour a small amount of the sauce into the bottom of a baking dish.
Place about 2-3 spoonsful of the spinach and basil mixture onto the end of each slice of baby eggplant and roll tightly, placing them seam side down on top of the sauce in the baking dish.
Pour the remainder of the sauce overtop the rolls and bake in the oven for 15 minutes.
Serve straight from the oven sprinkled with parmesan and chopped basil.