Preheat the oven to 180 ° C (convection 160 ° C). Place 14 paper baking cases in the muffin tray.
Wash, peel, halve, core and cut the apples into cubes. Drizzle with lemon juice. Mix the flour with baking powder. Whisk the egg. Add the sugar, vanilla sugar, oil, yoghurt and apple cubes with the egg to the flour mixture. Pour the dough into the molds and smooth out. Bake in the oven for about 30 minutes.
Then let the muffins rest for about 5 minutes, remove them and let them cool down.