In a small heavy saucepan over medium heat, combine 1 cup sugar, glucose syrup and water
Bring to a boil and cook without stirring until candy thermometer reaches 230 F
Meanwhile beat egg whites on medium speed until soft peaks form. Gradually add remaining extra 1 tsp sugar until peaks are very fluffy and soft.
When the syrup reaches 230 F, reduce mixer speed and pour syrup down the side of the bowl with the egg whites.
Increase speed to med-high and beat until cool-about 7 minutes. Add vanilla and beat until fully incorporated
The frosting should be shiny and fluffy and hold stiff peaks. Use immediately
