Preheat the oven: Set your oven to 350°F (180°C). Grease and flour an 8-inch round cake pan to prevent sticking.

Prepare the apples: Peel and slice the apples into thin wedges and set them aside.

Mix the batter: In a mixing bowl, blend the melted butter and sugar together. Add in the eggs, one at a time, stirring to incorporate them fully.

Combine dry ingredients: In a separate bowl, whisk together the flour, baking powder, cinnamon, and salt.

Combine mixtures: Gradually add the dry mixture into the wet mixture, stirring until just combined. Avoid over-mixing as it can lead to a denser cake.

Prepare the cake: Pour half of the batter into the prepared cake pan. Layer the apple slices over the batter and then pour the remaining batter on top, lightly spreading it to cover the apples.

Bake: Place the cake in the preheated oven and bake for about 30 minutes, or until a toothpick inserted into the center comes out clean.

Cool and serve: Let the cake cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.