Make a syrup placing sugar and water in a small saucepan over medium heat: bring to a simmer and cook for 2 minutes until sugar dissolves. Remove from heat and let cool, then chill it for 2 hours. Combine ASTI Secco Docg, vodka, syrup, blackberries, lime, and the mint leaves. Place the orange slices on a baking sheet with baking paper, bake at 220 F for about 3 hours and turn them every 30 minutes. Garnish the glass with orange, mint, and blackberries.