Prepare foil or parchment paper covered cookie sheet with at least 1 cup chopped walnuts or almonds
Make an oval shape with the nuts and set aside.
Place butter, sugar, vanilla, and salt in a skillet. Cook over medium- high heat.
Stir constantly until mixture turns the color of a brown paper sack.
Candy will start to smoke when it is ready to pour.
Immediately pour the mixture over the nuts on the cookie sheet. (Don't scrape the candy out of the pot, just let it fall out on its own).
Spread melted chocolate or sprinkle chocolate chips over toffee.
If using chocolate chips, spread evenly over toffee once they are melted.
Garnish the top of the chocolate with your chopped-toasted nuts. *This step is mostly for looks and is optional.
Allow the toffee to cool and set up for a few hours before breaking into small chunks. Process can be sped up in a fridge or outside in the cold weather.