Heat the cream, milk, sugar and caramel vanilla sugar while stirring. Whisk the egg yolks and eggs. Gradually add the hot cream, then the liqueur. Pour through a fine sieve.
Place four ovenproof flat moulds (approx. 14 cm Ø; 200 ml capacity) on a fat pan. Spread egg cream in them. Place in the preheated oven (electric cooker: 125 °C/circulating air: 100 °C/gas: level 1).
Pour on boiling water until the moulds for approx. 2⁄3 are in water. Leave to stand for 50-60 minutes. Leave to cool, chill overnight.
Sprinkle the advocaat cream with 1 tablespoon of brown sugar each. Caramelize with a kitchen gas burner until golden brown and decorate with mango wedges.