Preheat charcoal in a charcoal chimney. Once the charcoal has ashed over along the edges, set up grill for two-zone cooking by placing the briquets on one side of the charcoal grate to create a hot and a cool zone. Add 2–3 chunks of your favorite smoking wood and adjust the grill's bottom vents to bring the temperature to approximately 400°F.
Wrap each apple tightly with overlapping slices of bacon, starting from the bottom and working your way up until completely covered. Secure the end of the final strip of bacon with a toothpick.
Place bacon wrapped apples on the cool side of the grill, cover, and allow them to cook for approximately 20 minutes until the bacon is brown and crisp and the apple has softened.
Remove the apples from the grill, insert popsicle sticks in to the top of each apple, and allow them to cool in the fridge.
Heat the brown sugar, butter, corn syrup, milk, bourbon and vanilla extract in a small saucepan over medium heat. Insert a candy thermometer into the saucepan making sure that it doesn't touch the bottom. Allow the mixture to simmer until it reaches a temperature of 245°F. Remove from the heat and stir for 2–3 minutes until the bubbles subside and the caramel has thickened slightly.
Dip the apples into the caramel so that the bottom half is covered. (Note: you may want to insert a few toothpicks into the bacon to keep it in place as you coat the apple with caramel) Remove the apples and set on a greased sheet pan or plate and allow to cool before serving.