Combine butter, sugar, salt, and vanilla, and bring to a boil. Stir vigorously until sugar and butter are combined.
Continue cooking until the mixture is light brown in color and crack stage (300 degrees) has been reached.
Pour onto baking sheet (with sides) and spread thin. Sprinkle chocolate chips over the hot candy and allow to melt. Use a fork to spread the melted chocolate evenly over the candy. Sprinkle the finely chopped nuts on top.
When cool, break into pieces.