Preheat the oven to 180°C (350°F). In a bowl, combine sliced apples, brown sugar, cinnamon, and lemon juice. Set aside.

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 butter mixture, mixing until just combined.

Pour half of the batter into a greased 9-inch round cake pan. Layer the apple mixture on top, then pour the remaining batter over the apples.

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

Allow the cake to cool in the pan for 10 minutes before transferring to a wire rack. Serve warm or at room temperature.