Quickly dip each ladyfinger into the milk (do not soak). Arrange in a single layer in a 20×20 cm pan.
In a mixing bowl, combine mascarpone and powdered sugar and beat briefly until smooth.
Roughly chop/crush 10 Giotto balls and add them to the bowl. Add the cold whipping cream. Whip until thick and firm.
Spread the filling evenly over the ladyfingers. Refrigerate for 1 hour.
Heat 150 ml cream until it comes to a boil. Pour over the chopped hazelnut milk chocolate. Let stand 1–2 minutes, then stir until smooth.
Pour the chocolate topping over the chilled filling and spread gently if needed.
Decorate with Giotto balls. Refrigerate for 2 hours (or until set), then slice and serve.