Caramelized Apple Old Fashioned
https://www.themanual.com/food-and-drink/caramelized-apple-old-fashioned/

Ingredients:
2 oz bourbon
1 oz homemade caramelized apple syrup*
2 dashes Angostura bitters
1 dash of cinnamon bitters
1 thin apple slice
Cinnamon stick
Method:
In a mixing glass, combine bourbon, caramelized apple syrup, and bitters. Add ice and stir.
Strain the mixture into a rocks glass filled over a large ice cube.
Garnish with a thin apple slice and a cinnamon stick.
Caramelized Apple Syrup
Ingredients:
1 large green apple, peeled and chopped
1/2 cup brown sugar
1/2 cup water
1/4 tsp cinnamon
Method:
In a medium saucepan, melt the brown sugar over medium heat until it starts to bubble and form a caramel. Stir occasionally to ensure it doesnt burn.
Add the chopped apple to the pan and let it cook, stirring for a couple of minutes until it softens and absorbs some of the caramel.
Add water and cinnamon, stirring until the mixture reaches a syrup-like consistency. Simmer for 10-15 minutes.
Strain the syrup through a fine mesh sieve, discarding the apple pieces and solids, and let it cool to room temperature.