In a small pot over medium heat, whisk sugar and water until the water has dissolved.
Add 3/4 cup blackberries. Allow to simmer for four to five minutes, or until blackberries release their juices. Remove from heat and strain mixture to remove blackberries from the simple syrup. Allow to cool completely before making mimosas.
Pour a splash of the syrup into each serving glass. Gently top with sparkling wine.
To create an ombre effect, don’t pour the sparkling wine directly into the glass. Place a spoon on top of the glass and pour it over the spoon.