First, make the apple thyme simple syrup. Add the diced apples, water, sugar, and dried thyme to a small saucepan and bring to a boil. Once boiling, reduce the heat to a simmer and cook together for 10-15 minutes, stirring continuously. The syrup is ready when the liquid has begun to turn a very light brown and caramelize and the apples are beginning to soften.
Remove the simple syrup from the heat and add to a container to cool completely before using. I recommend storing the simple syrup in the fridge for 1-2 hours for the best flavor, but this is optional.
Once the syrup has cooled, add it to a cocktail shaker and muddle the apples until all the juice has been released. Then, fill the cocktail shaker with ice and shake vigorously to chill.
To make one cocktail, fill up a cocktail glass with 2-3 large ice cubes. Then, add in 3 oz apple thyme simple syrup, 1.5 oz bourbon, 1 oz freshly squeezed lemon juice, and top with 3 oz soda water. Stir together and then garnish with fresh apple slices and dried thyme. Serve and enjoy!