01 -
Line a baking sheet with parchment paper and measure all ingredients for easy access.
02 -
Melt unsalted butter in a heavy-bottomed saucepan over medium heat. Stir in granulated sugar and salt continuously until the mixture reaches 149°C (300°F) or a deep amber color with a nutty aroma.
03 -
Remove the saucepan from heat and immediately stir in vanilla extract, taking care as it will bubble briefly.
04 -
Pour the hot toffee onto the prepared baking sheet and use a spatula to spread into an even layer. Allow it to cool for approximately 2 minutes.
05 -
Sprinkle semi-sweet chocolate chips evenly over the warm toffee. Wait 1-2 minutes for the chocolate to soften, then spread smoothly using an offset spatula or knife.
06 -
Evenly scatter chopped nuts over the melted chocolate layer, and optionally sprinkle flaky sea salt. Let the toffee cool completely at room temperature or refrigerate to accelerate setting.
07 -
Once set, use a sharp knife or hands to break the toffee into shards for serving.