Mix the mascarpone, yoghurt and vanilla sugar with a whisk to a smooth mixture. Wash the raspberries and stir in as well; they can be mucked up a bit. Set aside some raspberries for decoration.
Then crumble the biscuits in a bag.
Depending on your preference, alternately layer the cream and biscuit crumbs in the dessert bowls, or stir directly into the cream.