Separate the egg yolks from the whites. Beat the egg whites until stiff peaks form.
In a mixing bowl, combine the egg yolks, sugar, lemon zest, ricotta, and cornstarch. Gently fold in the whipped egg whites until the mixture is smooth and airy.
Pour the batter into a 8-inch (20 cm) cake pan.
Bake in a fan-forced oven at 350°F (180°C) for 45–50 minutes, or until golden and set.
Let cool before slicing.
