Preheat oven to 350°F. Lightly grease six custard cups, or six 3 ½ - inch ceramic ramekins.
Melt butter and stir in the cookie crumbs. Press 1/3 cup of the mixture into the bottom of each of the ramekins. Place the ramekins in a baking dish or on a cookie sheet and chill until firm.
Meanwhile, finely grate the rind and squeeze the juice from the lemons.
Add the ricotta, yogurt, eggs, cornstarch, Rodelle Vanilla Bean, split and scraped, and sugar and whip until a smooth batter is formed.
Carefully pour the batter into the ramekins. Leave the ramekins in the baking dish or on the cookie sheet and bake for 35-40 minutes, or until just firm and golden brown.
Cool the cheesecakes completely in their cups or ramekins then run a knife around the edges to loosen, and turn onto individual serving plates.
Decorate with the lemon zest and dust with powdered sugar.
