Combine the vodka, lime juice, Simple Syrup, cherry juice and mint leaves in a shaker with ice. Shake until chilled and strain into 4 martini glasses. Top each glass with champagne and serve.
Combine the sugar and 1 cup water in a small saucepan and bring to a boil. Cook, stirring, until the sugar dissolves. Remove from the heat and let cool completely. Keep covered in the refrigerator up to 1 month.