Combine brown sugar, corn syrup and butter in a 1-quart saucepan. Stirring frequently, bring to a full boil over medium heat and boil 1 minute.
Remove from heat; immediately stir in cream and vanilla. Cool. Store in refrigerator. Microwave 30 seconds and stir before serving.
This delectable sauce is pourable hot or cold. Serve over ice cream, fruit pies or pound cake!