Preheat oven to 350°F (175°C).

Cream the butter and sugar together in a bowl until light and fluffy.

Add the eggs one at a time, beating well after each addition.

In a separate bowl, whisk together the flour and baking powder.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Pour the batter into a greased and floured cake pan.

Arrange the thinly sliced apples in a circular or linear pattern on top of the batter.

Bake for 60 minutes, or until a toothpick inserted into the center comes out clean.

Let the cake cool in the pan for a few minutes before transferring it to a wire rack to cool completely.