Preparation:

Preheat your oven to 350°F (180°C). Line the base and sides of an 8-inch (20 cm) round cake tin with parchment paper.

Making the Batter:

Place 1/2 cup of the caster sugar and the lemon zest in a food processor. Blitz until finely ground.

In a large mixing bowl, beat the butter, vanilla extract, and the sugar-lemon zest mixture together for about 10 minutes, or until the mixture is pale and creamy.

Add the egg yolks one at a time, beating well after each addition.

Add the almond meal to the mixture and beat until combined.

Gently fold the ricotta into the almond mixture until well incorporated.

Incorporating Egg Whites:

In a clean bowl, beat the egg whites until soft peaks form.

Gradually add the remaining caster sugar to the egg whites, whisking until stiff peaks form.

Mix one-third of the egg white mixture into the cake batter to lighten it.

Gently fold the remaining egg whites into the batter until no white streaks remain.

Baking:

Pour the cake batter into the prepared cake tin and smooth the top with a spatula.

Sprinkle flaked almonds evenly over the top of the batter.

Bake in the preheated oven for 40-45 minutes, or until the cake is firm to the touch and a toothpick inserted into the center comes out clean.

Allow the cake to cool completely in the tin before removing.

Serving:

Once the cake has cooled, remove it from the tin and dust the top with powdered sugar before serving.