English Treacle Toffee

I remember treacle candy from when I was in England. One of the stories I read every year with my European Lit class mentions it and I was going to take some to class, but I couldn't find anywhere. Finally found this recipe. :)

1 lb dark brown sugar
8 oz blackstrap molasses
4 oz unsalted butter
2 Tbls water
1 Tbls white vinegar

Place butter, water and vinegar in a saucepan; heat gently until butter has melted.

Add sugar and molasses and allow to dissolve (about 20 minutes).

Boil mixture to a temperature of 280° on candy thermometer. Remove from heat; allow bubbling to decrease.

Pour into a well greased 8" square pan.
When cooled, score surface into small squares with an oiled knife.
When cold, break into squares; wrap in cellophane and store in an airtight container.