Preheat your oven to 180°C (350°F). Line the cake pan with parchment paper. Lightly grease the sides with butter. This prevents the cake from sticking. Proper pan preparation also helps the cake bake evenly and release easily after baking.

Peel the apples and cut them into small cubes. Place the sultanas in warm water for ten minutes. Drain them well before using. This step keeps the fruit soft and juicy inside the cake.

Place softened butter and sugar in a mixing bowl. Beat them together until light and fluffy. This step adds air to the batter. The cake becomes soft and tender because of this simple mixing process.

Add the eggs one at a time. Mix well after each egg. Pour in the vanilla extract and stir again. The batter should look smooth and creamy. This helps create a rich and balanced cake flavor.

In another bowl, combine flour, baking powder, salt, and cinnamon. Stir them gently with a spoon. Mixing dry ingredients first helps distribute the baking powder evenly throughout the cake batter.

Add the flour mixture slowly to the butter mixture. Pour in the milk while mixing. Stir gently until everything is combined. Do not overmix the batter. Gentle mixing keeps the cake soft.

Add the diced apples and drained sultanas to the batter. Fold them in using a spatula. Make sure the fruit spreads evenly. This ensures every slice has sweet fruit inside.

Pour the batter into the prepared cake pan. Spread the top evenly with a spatula. Sprinkle brown sugar lightly over the top. This creates a slightly crisp and caramel-like surface after baking.

Place the cake in the preheated oven. Bake for about 45 minutes. Check the center with a toothpick. If it comes out clean, the cake is ready. The kitchen will smell amazing while it bakes.

Remove the cake from the oven and let it cool in the pan for ten minutes. Then move it to a cooling rack. Allow it to cool completely before slicing. This keeps the cake structure perfect.