Line a baking sheet with parchment paper.

In a medium saucepan, melt the butter over medium heat.

Add the brown sugar and salt; stir continuously until boiling.

Once boiling, let it cook without stirring for 3-5 minutes until it reaches a deep amber color.

Carefully pour the hot toffee onto the prepared baking sheet and spread it evenly.

Immediately sprinkle the chocolate chips over the hot toffee and let sit for a minute.

Spread the melted chocolate over the toffee with a spatula.

If using, sprinkle chopped nuts over the chocolate and gently press them in.

Allow to cool completely at room temperature before breaking into pieces.