In a glass, muddle mint and turbinado syrup. With the muddler still in the glass, pour in cognac and 2 ounces of sparkling wine (pouring over the muddler to rinse remaining herb flavors into glass). Fill glass halfway with ice and stir. Top with additional ½ ounce sparkling wine and garnish with mint, champagne grapes, and a dusting of powdered sugar.
From Mastering Mardi Gras.