Chop the mint leaves. In a small pot with a lid, combine the sparkling wine, anise, cinnamon, and mint. Cook over medium-high heat until the liquid is reduced by half, 5 to 7 minutes. Add the strawberries and the sugar, bring to a boil and cook, stirring, for 2 minutes, then immediately remove from the heat. Cover the pot and let the strawberries macerate, stirring occasionally, for 2 hours at room temperature. Remove the star anise and cinnamon stick. Divide the berry mixture among 6 glasses, add a few ice cubes, top each with a mint leaf, and serve.