Preheat the oven to 375°F (190°C).
Slice the eggplants into ¼-inch (0.6 cm) thick rounds. Lay them out on a baking sheet.
Drizzle the olive oil over the eggplant slices. Season both sides with salt and pepper.
Bake in the oven for about 20 minutes, or until the slices begin to turn slightly golden.
While the eggplant is baking, prepare the sauce. In a pan over medium heat, sauté garlic until fragrant. Pour in the tomato sauce, add a pinch of salt, black pepper, and red pepper flakes. Let it simmer for 10 minutes.
Remove eggplant slices from the oven. Spread a layer of tomato sauce on each slice, then sprinkle a generous amount of mozzarella and parmesan cheese.
Put the cheesy eggplant slices back into the oven and bake for an additional 20 minutes, or until the cheese is melted and bubbly.
Once done, sprinkle fresh basil on top before serving.