Prepare the Mandarins: Peel the mandarins and cut them in half, setting them aside.
Whisk the Eggs: In a large mixing bowl, whisk the eggs with 1 cup of sugar (200g) until the mixture turns creamy and light.
Combine the Milk: Gradually add the milk into the egg mixture and whisk until well blended.
Incorporate the Butter: Add the melted butter to the mixture and stir until fully incorporated.
Mix Dry Ingredients: In a separate bowl, combine the vanilla sugar, baking powder, and flour, then mix it into the wet ingredients until you achieve a smooth batter.
Fold in Apples: Dice the apples and carefully fold them into the batter, ensuring they are evenly distributed.
Prepare the Tray: Sprinkle 1 tbsp of sugar onto a tray lined with baking paper. Place the mandarin halves with the convex side facing up on the tray.
Add the Batter: Pour the prepared batter over the mandarin halves, leveling it out gently.
Bake: Place the tray in a preheated oven at 360°F (180°C) and bake for about 45 minutes or until a toothpick inserted in the center comes out clean.
Cool and Serve: Once baked, remove the cake from the oven and allow it to cool. Transfer the cake onto a cutting board, peel off the baking paper, slice, and enjoy!
