Cut apricots and heat in a pot with one tablespoon of cane sugar and a bit of lemon juice. Scrape out the vanilla pod pith. Add both the pith and the vanilla pod and bring to the boil. Remove vanilla pod and puree finely. Let cool.
Heat milk and cream in a pot but do not boil. Beat eggs with sugar in a metal bowl and carefully stir in the hot milk mix. Stir with a wooden spoon in the water bath until it thickens (the cream should get a creamy-liquid consistency). Then let cool.
Mix the cold apricot puree with the cold cream. You can then fill it into the icemaker and prepare it according to the producer's instructions. If you don’t have an icemaker, you can fill it into a bowl and put it into the freezer. Stir well every 20-30 minutes to avoid ice crystal formation. Shortly before the apricot ice cream is frozen, you put the jam on the surface by the spoonful so that the ice cream gets swirled or marbled. Then let freeze. Defrost the ice cream for about 10 minutes before portioning it.