2 sticks butter
1/2 c. white Karo syrup
2 c. brown sugar
1 tsp. vanilla
1/2 tsp. baking soda
6 qts. popcorn

Combine butter, Karo syrup and brown sugar in large saucepan, cook over medium heat. Stir until it comes to a boil. Allow it to boil for 5 minutes. Remove from heat and add vanilla and baking soda. Pour hot caramel over popcorn in two 9 x 13 inch pans.