Preheat the oven to 180°C (350°F). Grease and flour a cake pan.

In a mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.

Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

In another bowl, whisk together the flour, baking powder, and salt. Gradually add to the wet mixture, mixing until just combined.

In a separate bowl, combine the sliced apples, brown sugar, cinnamon, and lemon juice. Toss to coat the apples evenly.

Pour half of the batter into the prepared cake pan. Layer the apple mixture on top, then pour the remaining batter over the apples.

Bake in the preheated oven for 40-45 minutes, or until a toothpick inserted into the center comes out clean.

Allow to cool slightly before serving. Enjoy your Apfelkuchen!