1 c. butter
2 c. firmly packed brown sugar
1/2 c. light corn syrup
1 tsp. salt
1/2 tsp. baking soda
1 tsp. vanilla
6 qts. popped popcorn

Mix butter, brown sugar, salt and corn syrup. Bring to boil, stirring constantly. Boil without stirring for 2 minutes. Remove from heat and add baking soda and vanilla. Pour over popped popcorn.

Bake at 250°F in oven for 1 hour stirring every 15 minutes. Remove from oven and cool. Break apart.