Caramel Popcorn

This is my favorite homemade caramel popcorn...Enjoy!

1 bag popped popcorn (butter or plain)
3 TB light corn syrup
6 TB butter
3/4 cup packed brown sugar
1/4 tsp baking soda
1/4 tsp vanilla

1. Remove all unpopped kernels from popped popcorn. Pour into a 17x12x2-inch baking or roasting pan. Keep popcorn warm in 300 degree oven while making caramel.
2. For caramel, in a medium saucepan combine brown sugar, butter, and corn syrup. Cook and stir over medium heat until mixture boils. Continue boiling at a moderate, steady rate, without stirring, for 5 more minutes.
3. Remove saucepan from heat. Stir in baking soda and vanilla. Pour caramel over popcorn and stir gently to coat. Bake in 300 degree oven for 15 minutes. Remove from oven and stir. Bake 5 minutes more. Spread caramel popcorn on a large piece of buttered aluminum foil to cool. Store tightly covered for 1 week in refridgerator. You may also freeze this in a ziploc bag or container.