Add the brown sugar, water, and apple chunks to a small saucepan. Bring the mixture to a boil and simmer for an additional 20 minutes, stirring occasionally.
Once the apples are soft, pour the mixture through a strainer positioned over a bowl. Using a spoon, crush the apples to remove as much of the juice as possible. Once you've removed what you can from the apples, pour the syrup into a jar. For the ultimate frosty drink, allow the syrup to cool in the fridge for at least 1 hour before assembling the drink. If you're using premade apple syrup, skip the first 2 steps.
Combine the hot water and espresso in a French press. After 6 minutes have passed, push the plunger down and pour the coffee into a Mason jar for storage in the fridge for up to 3 days. As with the syrup, if you're looking for a frigid drink, allow it to cool in the refrigerator before assembling it. If you have an espresso machine, simply pull 2 shots of espresso and allow them to cool before assembling.
Combine the caramel syrup, whipping cream, skim milk, and sea salt in a small bowl or milk frother. Froth to your desired consistency.
Once it's time to assemble the drink, fill your favorite glass with ice, followed by approximately 1/4 cup of strongly brewed coffee or 2 shots of espresso. Add 1-2 teaspoons of the apple syrup and 3/4 cup milk and stir to combine. Finish with a dollop of the salted caramel cold cream foam, and enjoy!