Orange biscuits, up to 4 to decorate, roughly crushed and sprinkled with liqueur. Pour milk into a mixing bowl, add cream powder and whisk with the whisks of the hand mixer on lowest setting, then beat creamy for about 3 minutes on highest setting.
Pour the sprinkled cookies into 4 dessert glasses, spread the cream over them and put them in a cool place. Beat the egg yolks, sugar and egg liqueur in a hot water bath until a viscous mixture is formed.
Spread the sauce over the cream and decorate with the orange cookies. Serve decorated with mint leaves and chocolate shavings as desired.