In a saucepan over medium-high heat, add together all ingredients (stirring them to combine) and bring to a boil, about 1-2 minutes.
Reduce the heat to low and simmer for another 1-2 minutes or so. Remove from heat and let cool completely.
TO MAKE THE KAHLUA SUBSTITUTE:
In a saucepan over medium-high heat, add the water and brown sugar, stirring until sugar has dissolved completely, about 1-2 minutes. Remove from heat and whisk in the espresso powder until dissolved. Let cool.
TO MAKE THE MARTINI:
Add all of the martini ingredients together in a cocktail shaker with a bit of crushed ice, shaking well until combined.
Assemble the martinis: For each martini,fill a good cocktail or martini glass halfway with crushed ice and pour the apple caramel espresso martini mixture in each glass(es) until it's filled ¾ of the way. Top with apple slices, fresh rosemary sprigs, drizzle of caramel, or your favorite garnish.
Sip and Enjoy!
Notes
KAHLUA: Kahlúa coffee liqueur is one of the main ingredients in many of the world's favorite cocktails. Therefore, to make this recipe non-alcoholic----I created a great simple syrup substitute.
ALCOHOL: If you'd like to keep this recipe dairy-free, but want to spruce things up with alcohol, feel free to add 1 ounce of rum, vodka, etc.
SERVING: To make additional martinis, simply double or triple ingredients, depending on need.