Ingredients:

1 cup butter or margarine
2 1/4 cups packed brown sugar (16oz bag)
1 can sweetened condensed milk
1 cup light corn syrup
1 tsp vanilla

Procedure:

Line 8x8x2 or 9x9x2 pan with foil, extend over edges.  Butter foil.In saucepan, melt butter.  Add sugar, milk, and corn syrup.  Cook and stir constantly over medium-high heat until boiling.  Continue to stir until mixture reaches firm ball stage (15-20 minutes), 248 degrees (If you drop mixture into ice water, it will form a ball, but flatten when you pick it up).    Remove from heat and add vanilla.  Pour immediately into pan.  Let set until firm.  Pop out of foil and cut into 1 inch squares with a buttered knife and wrap in plastic wrap.  Keeping in fridge will keep it fresh.  Great over popcorn.  I like to cut them into smaller pieces, refrigerate and then dip in chocolate (using toothpicks or even better, city chicken sticks to help dip works well).  Cool on wax paper.