Prepare the Apples: Peel, core, and slice the apples into thin wedges. In a small bowl, toss them with 2 tablespoons of sugar and the juice of half a lemon. Let them sit for 5–10 minutes to release their natural juices and prevent browning.

Preheat the Oven: Set your oven to 180°C (350°F). Grease a round or rectangular baking pan with butter or line it with parchment paper.

Mix the Wet Ingredients: In a large mixing bowl, whisk together the eggs, 140 g sugar, vanilla sugar, and a pinch of salt until the mixture becomes light and fluffy. Gradually add in the milk, yogurt (or sour cream), and vegetable oil. Stir in the lemon zest for that refreshing citrus aroma.

Add the Dry Ingredients: Sift together the flour and baking powder. Gradually fold the dry mixture into the wet ingredients, stirring gently until the batter is smooth and lump-free. The consistency should be thick but pourable.

Assemble the Cake: Pour half of the batter into the prepared pan. Arrange half of the apple slices evenly over the batter. Pour in the remaining batter, then layer the rest of the apples on top in a decorative circular or spiral pattern.

Add the Finishing Touch: Brush the top of the apples with melted butter for a glossy finish and sprinkle a little sugar on top if you want extra caramelization.

Bake: Place the cake in the preheated oven and bake for about 40–45 minutes, or until a toothpick inserted into the center comes out clean and the top is golden brown.

Cool and Serve: Allow the cake to cool slightly before removing it from the pan. Serve it warm or at room temperature, dusted with powdered sugar if desired. It’s delicious on its own or served with a dollop of whipped cream or a scoop of vanilla ice cream.