To clean the apples, boil for 30 seconds to remove the wax like coating. Allow to dry and come to room temperature before dipping. To make the mini apples, use a small cookie scoop, and scoop out balls from the apple. Arrange on a baking sheet, and stick a tooth pick into each apple. If making full sized apples, use a lollipop stick, and place in the stem of the apple.
Arrange toppings in small bowls. You will need to work somewhat quickly once you start dipping, so the caramel does not harden.
In a large saucepan mix together butter, brown sugar, sweetened condensed milk and corn syrup. Stirring frequently, heat the mixture to 246 degrees. If you do not have a thermometer, drop a small amount of the liquid into a bowl of cold water. If it forms a soft ball it is done. Remove from heat, and stir in the vanilla extract. Let the caramel cool for 3-5 minutes before dipping the apples.
Dip each apple into the caramel. Gently tap the stick on the side of the pan, and spin to remove the excess caramel. Dip in desired toppings. Place on baking sheet to cool. Allow the caramel to cool completely before serving.