Fleur de Sel Toffee

8 oz. salted butter
8 oz. sugar
1 tsp salt
3 tbsp. water
1 tsp. vanilla
Fleur de Sel

Combine butter, sugar, salt, and water in a saucepan. Cook over medium heat stirring constantly until it reaches 300 degrees, remove from heat and stir in the vanilla. Pour onto a silicone mat or parchment and spread thin, sprinkle lightly with fleur de sel. Score, let cool and break into pieces.