Rinse the ramekins (125 ml capacity each) with water and cover with cling film. Fill ramekins two-thirds full with berries, set aside remaining berries for garnish. Place ramekins in the freezer for 20 min.
Soak gelatine in cold water, squeeze well and warm up with the liqueur, mix in powdered sugar.
Remove the ramekins from the freezer. Stir the still warm gelatine and the Prosecco quickly and spread evenly over the berries. Cover with plastic wrap and place a board over the top (this keeps the surface smooth). Leave the Prosecco berries to cool.
For the sauce, whisk together yogurt, lime juice and powdered sugar until smooth. 5.
Spread the sauce evenly on the plates. Invert the berry sauce into the center and decorate with the remaining berries, lemon balm or mint.
Tip: Use creamy natural yogurt for an even finer result!