Why an Invisible Apple Cake you ask? The magic trick comes from the very thinly sliced apples coated with a minimal amount of batter. When the cake is sliced the apple are practically invisible.
Place a piece of parchment paper at the bottom of a 6-inch springform pan and grease sides and paper lightly. Preheat the oven to 400 F.
With a stand or electric mixer, beat the eggs and the sugar for about 3 minutes or until fluffy. Add the melted butter, the milk and vanilla, and mix till combined.
Mix the flour, baking powder, cinnamon and salt together. Add the dry ingredients to the wet ones and mix until just combined.
Cut the apples in quarters and with a mandolin slice each piece into 1/8 in (3 mm) thick slices. Put the apple slices into the bowl with the batter and very gently stir to coat them with a silicone spatula, ensuring each slice is coated but without breaking the apple slice.
Pour batter gently and evenly into the prepared pan. Sprinkle sliced almonds on top.
Bake in the oven for 60 minutes or until set. If the almonds brown to fast cover loosely with aluminium foil. Cool cake completely in the pan. When cooled remove the pan and dust with icing sugar before serving.