Baked Caramel Corn

1 C (2 sticks) butter or margarine

2 C firmly packed brown sugar

1/2 C light or dark corn syrup

1 t salt

1/2 t baking soda

1 t vanilla

6 qts. popcorn

Melt butter; stir in brown sugar, corn syrup and salt. Bring to boil, stirring constantly; boil without stirring for 5 minutes. Remove from heat; stir in soda and vanilla. Gradually pour over popped corn, mixing well. Turn into 2 large, shallow baking pans. Bake at 250 degrees for 1 hour, stirring every 15 minutes. Remove from oven, cool completely. Break apart and store in tightly covered containers. Makes 5 quarts.