01 -
Measure all ingredients and have them ready before starting. Line a baking sheet with parchment paper.
02 -
Lightly toast the chopped nuts in a dry skillet over medium heat until fragrant, about 3-5 minutes. Set aside to cool.
03 -
In a heavy-bottomed saucepan, combine butter, sugar, salt, and water. Cook over medium heat, stirring constantly until mixture reaches 285°F (140°C) on a candy thermometer.
04 -
Remove from heat and carefully stir in vanilla extract and half of the toasted nuts.
05 -
Quickly pour the hot toffee onto the prepared baking sheet and spread into an even layer. Let cool for 2-3 minutes.
06 -
While toffee is still warm, sprinkle chocolate chips over the surface. Once they begin to melt, spread the chocolate into an even layer. Sprinkle with remaining nuts and optional sea salt.
07 -
Allow toffee to cool completely at room temperature (about 2 hours) or refrigerate for faster setting. Once hardened, break into pieces.