Preheat oven to 350 degrees F. Cut parchment paper so that it is about 2 inches larger than the pan. Line 8-inch cake pan with parchment paper, allowing the paper to extend over the edges. Lightly coat with butter or cooking spray. Set aside.
In a small bowl, whisk together flour, baking powder, salt, cinnamon and nutmeg. Set aside.
In a large bowl, cream together softened butter, brown sugar, and granulated sugar. Add eggs and vanilla. Mix until combined. Add flour mixture and stir until just combined.
Transfer batter to prepared cake pan. Use the back of a spoon or a mini offset spatula to evenly distribute batter in pan.
Apple Topping: In a small bowl whisk together sugar and cinnamon. Add sliced apples. Toss to coat in cinnamon-sugar mixture. Arrange apple slices on top of batter in desired configuration.
Bake for 40-45 minutes until toothpick inserted in center of cake comes out clean. Let cool in pan for 10 minutes. Unmold by lifting excess parchment paper overhang. Allow to cool on wire rack. Serve warm or at room temperature. Garnish with powdered sugar, if desired.