Peel and slice the apples thinly.
Sprinkle apples with lemon juice to prevent browning.
In a separate bowl, whisk together eggs, salt, vanilla sugar, and sugar.
Add lemon zest, milk, and melted butter to the egg mixture and mix.
Gradually add sifted flour and baking powder to the wet ingredients, mixing until just combined. Be careful not to overmix.
Add the apples to the batter in portions, gently stirring to coat each slice without breaking them.
Grease a baking mold (16-18 cm) with butter and line with parchment paper.
Arrange the apple slices coated in batter into the mold in layers, pressing down gently to ensure they lie flat and there are no gaps.
Drizzle the top with 10-20g of melted butter.
Bake in a preheated oven at 180°C (350°F) for 50-60 minutes.
Let the cake cool completely.
Sprinkle with powdered sugar, if desired, before cutting and serving.
