2 c. packed brown sugar
1 c. butter
1 c. light corn syrup
1 tsp. salt
1 tsp. vanilla
9 qt. popped popcorn
1/2 tsp. baking soda

Mix these first 5 ingredients and boil for 5 minutes, stirring constantly. Add 1/2 teaspoon baking soda. Pour over popcorn in large pan. Put in oven for 1 hour at 225 degrees. Stir every 15 minutes. Spread on cookie sheet and cover with wax paper until cool. Break up and store in containers.