1 cup sugar
1/4 cup water
2 egg whites
2/3 cup blueberries
1 vanilla bean, split length wise
Beat the egg whites and salt to soft peaks using an electric mixer. Meanwhile, in a medium saucepan, bring sugar, vanilla bean blueberries and water to a boil, stirring occasionally, mashing the berries a bit with the back of your spoon. Continue to boil until it reaches soft ball stage (when a drop of the syrup forms a soft ball when dropped in cool water) while continuing to stir occasionally.
Whisk the mixture through a fine sieve into a heat safe measuring cup and discard the blueberries. Keep the mixer running (to be safe use a stand mixer or a friend to complete this next step) and pour a continuous stream of molten syrup into the egg whites. Continue to beat for about 5 minutes or until the frosting is fluffy, glossy and cool. Frost cooled cupcakes or cake.
The best word to describe this frosting is ethereal. It has an incredibly light and smooth texture and is infused with blueberries and vanilla. So good and perfect for summer.