Blackberry Milkshake with Whipped Cream
Rinse and pick over blackberries, then pat dry with paper towels. Set aside a few berries for garnish, if desired.
Combine remaining blackberries with lemon juice, powdered sugar and 1/2 teaspoon vanilla sugar in a blender. Add milk, quark and ice cream. Blend until smooth.
Whip cream and remaining vanilla sugar until stiff. Transfer whipped cream to a squeeze bottle or pastry bag fitted with a star tip. Divide milkshake among glasses and top with whipped cream. Garnish with reserved blackberries.