Roast the almonds without fat in a pan and let them cool completely.
Separate the eggs. Beat the egg yolks, powdered sugar and vanilla sugar until foamy. Gradually stir in the milk. Whisk the mixture in a double boiler until it forms a thick cream, making sure the bowl does not touch the water. Remove the cream from the heat.
Fold in the almonds and let everything cool, stirring frequently. Put the mixture in the freezer and let it become semi-solid, stirring occasionally. Beat the egg whites until stiff, fold in and allow to set. Allow to thaw for about 10 minutes before cutting. For the orange sauce, blanch the zest briefly in hot water.
Dissolve the cornstarch in the orange juice and heat together with the sugar and the liqueur. Add the zests. Simmer briefly while stirring. Add the butter, continue stirring briefly and then let cool. Arrange the iced almond cream on the orange sauce and decorate with orange slices and mint.