Made using all-purpose and corn flours, this easy cake batter is flavored with lemon juice for brightness. Whipped egg whites that are gently folded into the mix keep the cake light. Meanwhile, whipped cream and ricotta is thickened with unflavored gelatin for a memorably creamy filling that goes between the layers of baked cake. Allow time to refrigerate the assembled dessert overnight. Then, sprinkle it with powdered sugar before serving.