Toast the baguette slices in the oven for about 10 minutes at 400 degrees F, or in the air fryer for 3-4 minutes. Drizzle the crostini with olive oil and let cool.
Spread a light layer of ricotta onto each crostini. Season them with salt and pepper.
Layer on a 1/4 slice of prosciutto. Drizzle on the balsamic. Garnish each crostini with a small basil leaf.