From prettyintink:
7 to 8 cups popped popcorn
3/4 cup packed brown sugar
6 tablespoons butter
3 tablespoons light corn syrup
1/4 teaspoon baking soda
1/4 teaspoon vanilla
Remove all unpopped kernels from popped popcorn. Put popcorn into a 17X12X2 inch baking or roasting pan. Keep popcorn warm in a 300 degree oven while making caramel mixture.
For caramel mixture, 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 minutes more.
Remove saucepan from heat. Stir in baking soda and vanilla. Pour caramel mixture over popcorn. Stir gently to coat. Bake in a 300 degree oven for 15 minutes. Stir mixture, bake 5 minutes more. Spread caramel corn on a large piece of butterered foil to cool. Store tightly covered for up to 1 week.
From my cousin:
Microwave Carmel Corn
(I haven't tried this one yet, prettyintink also has a microwave recipe, I'll see if I can get it from her)
4 quarts popped popcorn (1 batch of hot air popped popcorn)
In a separate microwave safe bowl, place:
1 cup brown sugar
1 cube margarine (1/4 pound)
1/4 cup light corn syrup
1/2 teaspoon salt
Bring to a boil on full power. Boil for 2 minutes. Remove bowl from microwave and stir in 1/2 teaspoon baking soda. Stir until dissolved.
Put popcorn into a clean brown paper bag. Put in some syrup, close the top, shake, and repeat. Microwave 1 1/2 minutes in the bag.
Let it cool a bit before you eat any as it will be very hot.
Baked Caramel Corn
This is the recipe I tend to use. I've had this recipe for years and years.
It's from the Jollytime Popcorn Company (probably called something else by now). The taste is similar to Cracker Jack, don't know if you have something like Cracker Jack or not. Cracker Jack has peanuts in it. While the recipe doesn't call for nuts, sometimes I add them to the popcorn when I add the syrup anyway.
1 cup butter
2 cups brown sugar
1/2 cup light or dark corn syrup
1 teaspoon salt
1/2 teaspoon baking soda
1 teaspoon vanilla
6 quarts popped popcorn (no "old maids"-unpopped kernels)
Melt butter. Stir in brown sugar, corn syrup, and salt. Bring to a boil, stirring constantly. Boil without stirring for 5 minutes. Remove from heat. Stir in baking soda and vanilla. Pour over popped corn, mixing well. Turn into 2 large shallow pans (like large cookies sheets, the ones with sides on them). Bake in a 250 degree oven for one hour, stirring every 15 minutes. Remove from oven, cool. Break apart and store in a tightly covered container. Makes about 5 quarts caramel corn.