For Blackberry Ice Cubes
To prepare the blackberry ice cubes combine the sugar and water into a small saucepan, stir and simmer over medium heat until the sugar dissolves.
Remove from heat and add blackberries.
Allow the mixture to cool completely.
Once cool, pour into an ice cube tray and freeze for at least 4 hours.
For the Basil Lemonade
In small saucepan, combine sugar and 1 cup of water.
Heat, stirring frequently until sugar completely dissolves to create a simple syrup. Let cool.
In a large pitcher, combine simple syrup, lemon juice and 3 to 4 cups of cold water, until desired strength is achieved.
Chill in the refrigerator for at least 30 minutes.
Serve in tall glasses with blackberry ice cubes and fresh lemon slices.
Garnish with a sprig of basil.