Wash and dry the apples. You'll want to rub them really well with a kitchen towel or paper towel to remove any waxy residue. This will help the caramel stick to the apples better.

Place a caramel apple stick in the apples and refrigerate them until you are ready to dip.

In a heavy bottom pan, combine the brown sugar, heavy cream, corn syrup, butter, and salt. Cook this mixture over medium heat. Resist the urge to change the temperature while making the caramel.

Stir the caramel with a wooden or rubber spatula, just until the butter has melted and all the ingredients are well combined. Continue to stir occasionally to prevent sticking but don't over stir...it will cause bubbles in the caramel.

Continue to cook until the caramel reaches 235°-240° on your candy thermometer. This will take 15 to 20 minutes. It's okay if it takes a little longer, just don't raise the temperature. Remove the caramel from the burner and stir in the vanilla.

Hold the skewered apples by the sticks and dip into the caramel sauce. Tilt the pan if needed to fully coat the apples. Lift and swirl to let the excess caramel drip off, then place on the prepared paper lined pan. Let the apples sit for 30 to 60 minutes.

If you want to decorate your apples, do this right after you dip them so the sprinkles or salt will stick. If you want to drizzle with chocolate, you'll want to let the caramel set and cool completely first.