Peel, core and finely slice the apples. Don’t chop them because then they’ll get too mushy when being cooked. Bring to the boil with some water and let it simmer until apples are completely soft. Mix cornstarch with rum and add to the cooked apples. Bring to the boil once more, then remove from oven and let it cool completely.
Meanwhile you want to make your false mascarpone, as I like to call it. Gently whisk curd, yoghurt and sugar. If you want you can also add a tablespoon of rum. Crumble about 5-6 ladyfingers into smaller pieces and divide them between the glasses. On top, layer some of the yoghurt cream. Crush about 2-3 ladyfingers and sprinkle it on top of the yoghurt cream. This will prevent the tiramisù from getting all slobbery. Then layer apple cream, yoghurt, crushed biscuits until the glasses are full.
The tiramisù tastes best when cooled over night or at least for 2 hours.