Puree a handful of strawberries with the eggnog or juice. Halve the remaining strawberries, cut large ones even smaller if necessary.
Whip the cream with vanilla sugar until stiff. Mix the mascarpone, yoghurt and powdered sugar, fold in the cream. Layer half of the biscuits in a baking dish, soak half of the liqueur mixture, spread half of the strawberries on top and cover with half of the cream. Repeat the process with the remaining ingredients.
Let it soak in the refrigerator for at least two hours, or better overnight, dust with kaba powder before serving.