This recipe came from one of a Texas cookbooks called Longhorn Legacy.
Easy Caramel Corn
6 cups popped popcorn (microwave)
4 tablespoons butter
1/2 cup brown sugar
2 tablespoons light corn syrup
1/4 teaspoon salt
1/8 teaspoon baking soda
¼ teaspoon vanilla extract
Preheat oven to 250 degrees F. Spray a roasting pan with cooking spray; Spread popcorn in pan.
In a heavy saucepan, melt butter over medium. Add sugar, syrup and salt and bring to a boil. Boil, without stirring, for about 2 minutes. Turn off heat and stir in baking soda and vanilla. Pour over popcorn, mixing thoroughly.
Bake for 1 hour, stirring every 20 minutes. Let cool completely