Grease an 8″ cake pan.
In a large heavy saucepan, soften the butter.
Stir in remaining ingredients.
Stirring constantly, bring to a boil over medium high heat.
Candy thermometer should reach 260 degrees or hard ball.
Stir constantly as it will stick to the pan easily.
Pour into pan quickly and cool.
Tip: You may make a softer toffee by decreasing cooking time slightly.