Preheat oven to 430F (220C).

Remove eggplants' ends and slice them thinly lengthwise (about 5 millimetres or 0.2 inches thick).

Arrange eggplant slices on a baking sheet lined with parchment paper. You may need to use two baking sheets or bake eggplants in two batches depending on the size of your oven.

Spray with olive oil and season with salt and freshly cracked pepper. Bake for 25 minutes then remove from the oven and set aside. They will look a bit dry, it's normal (but they will actually be super tender).

In a bowl, combine tomato passata, 1 tablespoon of oregano and 2 teaspoons of basil.

In another bowl, mix together ricotta, 1 cup parmesan, eggs and the remaining oregano (1 tablespoon). Set aside.

In a 9×13' (23×33 cm) baking dish, arrange one layer of eggplant, one layer of tomato sauce and one layer of cheese mixture. Repeat with another layer of eggplant, tomato sauce and finish with cheese mixture. Sprinkle with remaining parmesan (½ cup).

Bake at 430F - 220C for 30 minutes or until cheese is golden brown. Please note that all ovens are different: keep an eye on the casserole and if it starts browning too much, reduce the oven temperature to 355F (180C).

Remove from the oven, cool slightly and then slice.