8 cups popped popcorn (about 1/2 cup unpopped)
3/4 cup packed brown sugar
1/3 cup butter
3 tablespoons light corn syrup
1/4 teaspoon baking soda
1/4 teaspoon vanilla

Preheat oven to 300ºF. Sort through the popped corn to remove any unpopped kernels. Place the popcorn in a large roasting pan or other deep pan, place in the oven to keep warm while you make the caramel.

Combine brown sugar, butter and corn syrup in a heavy saucepot over medium-high heat. Cook and stir to boiling. Carefully clip on a candy thermometer to the side of the pan. Continue to cook and stir to 255º, or hard-ball stage. This should take about 4 minutes.

Remove saucepot from heat and stir in vanilla and baking soda. Pour caramel over the popcorn and stir gently to coat the kernels.

Bake in a 300ºF oven for 15 minutes. Stir gently, return to oven, and bake for 5 more minutes.

Transfer popcorn to a large piece of foil or sheet pans to cool completely. Break up into clusters. Store tightly covered.

For Nutty Caramel Corn prepare as above, except add 1 1/2 cups peanuts, walnut halves, cashews, or pecan halves to the caramel coated corn before baking. Toss gently.