Grilled-Lime Caipirinhas

Ingredients

1. 1 lime
2. 2 tablespoons superfine sugar, plus more for dusting
3. Ice cubes
4. 3 ounces cachaça
5. 1/2 ounce lemon-lime soda (optional)

1. Light a grill or preheat a grill pan. Trim the ends off the lime and slice the lime crosswise 1/4 inch thick. Dust both sides of the lime wheels with sugar and grill over high heat, turning once, until lightly caramelized, about 20 seconds per side.
2. In a rocks glass, muddle the lime wheels with the 2 tablespoons of sugar. Fill the glass with ice, add the cachaça and soda, if using, and stir well.