Preheat oven to 400°F/200°C
Slice eggplants in half lengthwise. Place 12 slices of eggplant on a baking sheet. Depending on how big your oven is, you may need two baking sheets.
Bake for 10 minutes, then take it out of the oven and let cool.
While the eggplants cook, make the ricotta/spinach mix. In a bowl, combine ricotta, mozzarella ( 1/2 cup), parmesan, spinach, egg and garlic. Season to taste.
Place 1/2 cup tomato sauce in the bottom of a large baking pan.
Spread the ricotta/spinach mixture evenly on an eggplant slice (about 2 heaping tablespoons). Roll it up and place seam-side down in prepared dish. Continue with the remaining eggplant.
Sprinkle remaining tomato sauce (1/4 cup) on top.
Bake for 45 minutes, then cover with foil. Bake for 15 more minutes, or until cheese is golden brown. Bake for 10 minutes. Let cool in the oven.