6 egg whites
1 1/2 teaspoons cornstarch
1/2 cup water
1 teaspoon lemon juice
1 teaspoon vanilla extract
1 1/2 cups confectioners' sugar
1/2 teaspoon lemon zest
Combine egg whites, cornstarch and water in a glass or plastic bowl. Bring to a simmer over medium heat. Do not stir. Reduce heat to medium; simmer for 1 to 2 minutes. Let cool; pour into glass or plastic bowl. Refrigerate 2 hours or overnight. Flatten and pack. Store in tightly covered container in refrigerator.
In a medium bowl, combine lemon juice and vanilla extract. Set aside.
Combine lemon zest and 1/2 cup sugar; beat until frosting is spreadable. Fold into whipped cream.