Clean fresh berries, process frozen berries without defrosting. Puree raspberries and blackberries, up to 4 blackberries for decoration, with sugar in the universal salt chopper. Remove 2 tablespoons of berry puree.
Put milk and vanilla ice cream in the blender and whisk. Immediately pour into chilled glasses, add the rest of the berry puree and stir in with a wooden skewer. Decorate with blackberries.