Ingredients
16 oz. weight Butter, Melted
16 oz. (2 cups) weight Granulated Sugar
3 oz.  (6 tablespoons) fluid Water
1 tsp. Salt
1 tsp. Vanilla Extract
6 oz. (1 cup)  weight Tempered Dark Chocolate For Coating, Melted

Combine butter, sugar, water, and salt in a saucepan. Bring to a boil, stirring constantly.

Cook over moderate heat, stirring gently, until candy thermometer registers 298 degrees.

Remove from heat and stir in vanilla until well combined.

Pour the mixture onto a silicone baking mat or good parchment paper. Use a heatproof rubber spatula or offset spatula to spread quickly before the toffee sets. Spread thin.

Allow toffee to cool completely. Blot to remove excess oil from the surface. Coat surface with the melted chocolate.

Allow to set, then break into bite-size pieces.