Beat the eggs with the sugar until light and fluffy. Mix for several minutes until the colour becomes noticeably paler and the texture thickens slightly, as this incorporates enough air to help the cake rise evenly in the oven. The mixture should feel smooth, with the sugar starting to dissolve into the eggs for a stable base.
Add the oil and the natural yoghurt and mix well. Stir gently but thoroughly until the fats and liquids blend into a uniform mixture with no streaks. The oil gives the finished cake softness, while the yoghurt adds moisture and a subtle tang. Make sure the yoghurt is fully incorporated to prevent uneven pockets in the batter.
Add the flour and the baking powder and stir into a smooth batter. Sprinkle them evenly over the surface of the mixture before folding them in, which helps prevent lumps and supports an even rise. Mix only until the flour disappears; overmixing can lead to a denser texture. The batter should be smooth, slightly thick but still easy to pour.
Cut the apples into pieces and mix them together with the walnuts and cinnamon through the batter. Slice the apples into small, even cubes so they soften gently without breaking apart during baking. The walnuts add crunch, while the cinnamon disperses its aroma through the cake. Fold everything in carefully to distribute the ingredients without deflating the batter.
Pour the mixture into a cake tin of approx. 30 cm. Lightly grease the tin or line it with baking paper to ensure the finished cake releases easily. Smooth the top lightly if needed so the batter settles evenly and bakes uniformly.
Bake for 20 minutes in a preheated oven at 170 °C. During baking, the cake should rise gently and develop a light golden colour. It is ready when the surface springs b
