1 large peach – halved, stone removed, and skin on
1/4 cup white sugar
5 leaves fresh mint
2 fluid ounces simple syrup
3 fluid ounces bourbon (such as Bulleit®)
4 fluid ounces ginger ale, or as needed
Preheat an outdoor grill for medium-high heat and lightly oil the grate. When the grill is hot, close lid and allow to heat, 5 minutes.
Place peach halves and lemon, cut-side down, in sugar until coated. Place on the grill; cook until fruits are soft, about 5 minutes. Cool on a cutting board, about 1 minute. Cut peach into slices with a knife; reserve 2 for garnish.
Place remaining peach, mint leaves, and simple syrup into a cocktail shaker; juice lemon into the shaker. Gently muddle with a cocktail muddler. Pour in bourbon and ice, cover, and shake until the outside of the shaker has frosted. Strain into a chilled glass; top off with ginger ale, and garnish with grilled peach slices and lemon.