Insert wooden sticks into the top of each apple. Line a baking sheet with parchment paper.

In a medium saucepan, combine the heavy cream, butter, sugar, and corn syrup. Cook over medium heat, stirring occasionally, until the mixture reaches 240°F (soft-ball stage) on a candy thermometer.

Remove from heat and stir in the vanilla extract. Let cool slightly until the caramel is thick enough to coat a spoon.

Hold each apple by the stick and dip into the caramel, turning to coat evenly. Allow any excess caramel to drip off, then place on prepared baking sheet to set.

Let the caramel apples cool completely at room temperature before serving or decorating as desired.