Slice the aubergine into cubes; sprinkle with a pinch of salt and leave them for 3 minutes in a colander. Rinse with water, dry in a cloth and deep fry in 4 tablespoons olive oil. Leave them aside to drain on kitchen paper.
Cook the onion in a pan with 4 tablespoons of oil until golden brown; add the tomatoes and sauté until the water evaporates. Add garlic cloves, 4 leaves of chopped basil, salt and black pepper to taste.
Boil the fusilli in plenty of salted, boiling water; drain al dente and toss them in the pan with the tomato sauce and the aubergine cubes. Serve with grated ricotta cheese and remaining basil leaves.