1 c packed brown sugar
1/2 c heavy cream
4 TBS butter
pinch of salt
1 TBS vanilla
Melt butter in pot.
Mix in brown sugar, cream and salt.
Cook over medium-low heat and whisk gently for 7 minutes.
Remove from heat. Add vanilla and return to cook for another minute or two until it thickens some more.
Take off stove and pour into jar. Refrigerate.