Preheat oven to 325º F. Lightly grease 6 4-1/2 inches in diameter mini springform pans. Line the base and side with parchment paper. Set aside.
Beat butter and 3/4 cup of sugar in an electric mixer for 5 minutes, or until pale and creamy. Add vanilla and lemon and beat to combine. Scrape down the side of the bowl and add egg yolks, one at a time, and beat for 2 - 3 minutes until well combined.
In a medium bowl, combine the almond meal and cornflour. Add this mixture to the butter mixture and continue beating until combined.
In another bowl, place the egg whites and whisk until a stiff peak forms. Add the rest of the sugar (1/2 cup) and salt; continue whisking until thickened, about 2 minutes.
With a flexible spatula, fold in the egg whites and ricotta through the batter in two batches. The key is to go slow, and not to overdo it.
Divide the batter equally between pans and carefully smooth the tops with a knife. Decorate the cakes with almond flakes.
Bake for 35 - 40 minutes, or until a wooden skewer inserted in the center comes out clean.
Allow to cool completely, remove from pans, and dust with Confectioner's sugar.