In a thick bottomed, heavy duty pan, combine sugar, corn syrup, and water.
Slowly stirring, cook over high heat until syrup reaches 234F. When syrup hits 234F, turn your mixture on high to start whipping egg whites but continue cooking syrup.
Slowly stirring, cook syrup until 252F. Turn off heat.
Slowly stream hot syrup into whipping egg whites. This needs to be done slowly so you do not collapse egg white meringue.
Once all the syrup is added, continue whipping on high for four minutes.
Turn mixer to low and add browned butter and vanilla.
Add in powdered sugar.
Mix on high for 30 seconds to incorporate all ingredients.
Let cool to touch. Cover lightly and rest overnight, or for a minimum of 12 hours, before cutting.
Store cut pieces in an airtight container at room temperature.