To get the cake you truly deserve, sift the flour mixture twice to get the flour as aerated and light as possible, or give it a spin with cake or spelt flour. This recipe can be halved. To make one cake, halve the ingredients. To divide an egg, simply crack the egg into a small bowl, whisk, and use a tablespoon to measure half. Chef’s Notes: Alternatively, divide the batter evenly between the skillets or pans and smooth the tops with a spatula. Working from the center out, gently lay two-thirds of the apple slices on top of the batter; leave behind any excess juice. Brush or drizzle the melted butter over the apple slices. Mix the sugar and cinnamon together and sprinkle evenly over the apple slices. Bake for approximately 20 minutes, then for the decorative top, place the remaining one-third of the apple slices on top of the cake. Work quickly, so you don't lose all the oven's hot air. Cook for an additional 10 minutes or until golden. For the apples, alternatively, you can hasselback the apples and place them in the batter.