Preheat the oven to 400°F (200°C). Slice the eggplants and sprinkle with salt. Let them sit for 15 minutes to sweat out moisture.

Rinse the eggplant slices and pat them dry with paper towels. Brush both sides with olive oil and place on a baking sheet.

Roast the eggplant in the preheated oven for 20 minutes, flipping halfway through, until tender and slightly browned.

In a saucepan, heat a little olive oil over medium heat. Add minced garlic and sauté until fragrant.

Add crushed tomatoes, oregano, basil, red pepper flakes, sugar, and salt. Simmer for 15 minutes, stirring occasionally.

In a mixing bowl, combine ricotta cheese, half of the mozzarella, Parmesan cheese, egg, salt, and black pepper. Mix well.

In a baking dish, spread a layer of tomato sauce on the bottom. Layer with roasted eggplant, followed by the cheese mixture. Repeat the layers, finishing with tomato sauce and remaining mozzarella on top.

Cover the baking dish with foil and bake in the oven for 25 minutes. Remove the foil and bake for an additional 15 minutes until the cheese is bubbly and golden.

Let the lasagna cool for 10 minutes before slicing and serving.