Line cookie sheet with parchment, butter it, set aside.

In a medium sauce pan add the butter, sugar, water, salt. Bring to a boil stirring all the time.

Continue to cook over medium heat until temp reaches 298 degrees F, continue to continually stir.

Remove from heat, add the vanilla, stir.

Pour onto prepared baking sheet. Let set/cool completely.

Blot toffee with towel to remove extra oil from surface.

Melt 1/2 your chocolate, spread over the top of the toffee, sprinkle with half the walnuts and sprinkle with sea salt. Let set completely.

When ready, melt the second half of the chocolate.

Flip over the toffee, blot with towel.

Spread with melted chocolate, sprinkle with remaining walnuts.

Let set completely.

When ready to break you can either break it in rough pieces or cut with a large knife, run the knife under hot water first to get the blade warm, dry off and cut.

Store in airtight container.