1 c. melted butter
2 c. brown sugar
1/2 c. corn syrup
1 tsp. salt
1/2 tsp. baking soda
1 tsp. vanilla
6 qt. popcorn (2 pans full)

Bring butter, brown sugar, corn syrup and salt to a boil; stirring constantly. Boil without stirring for 5 minutes. Stir in soda and vanilla, pour over popcorn. Mix well and turn into 2 large shallow roasting or baking pans. Bake at 250 degrees for 1 hour, stirring every 15 minutes. Cool completely. Store in airtight container.