Mix all ingredients up to and including vanilla sugar. Divide quantity in half. Raspberries to one half form, blueberries to the other. Blend both separately in a hand mixer or possibly a cutter, arrange on the spot.
Divide the semi-frozen mixture evenly in champagne glasses. For the garnish, mix the curd cheese with the cream and fold it into the quantity with a fork in a marble-like manner, bring to the table on the spot.
Tips: Use blackberries instead of blueberries. Mix powder, curd, cream and vanilla sugar 3-4 hours in advance, put to cool with the lid closed. Just before serving, add berries, whisk or chop the whole.