Preheat your oven on 180'C / 350'F.Grease or line a 20cm/8inch round Springform Pan with baking paper.
Melt the Unsalted Butter in the microwave and set aside to cool down.
Peel, Core and Cut the Apples into small cubes. Set aside.
In a large mixing bowl, whisk the Eggs and Brown Sugar until foamy. Add the melted butter and Applesauce and stir until combined.
Whisk in the dry ingredients: Plain Flour, Baking Powder and Salt (and optionally Ground Cinnamon)
Mix the Apple slices directly into the cake batter, making sure all the apple cubes are equally covered with batter (1)
Pour the cake batter into the lined/grease pan and bake for 20 to 25 minutes (*), or until the tip of a knife comes out clean.
Serve warm with Whipped Cream or Vanilla Ice Cream, or leave to cool down completely. Optional: dust with a little bit of Icing Sugar and/or Cinnamon Powder.
Optionally, you can also keep about 1/4 of the cubed apples to place over the cake batter in the baking pan if you want to "show" more of the apples on the cake.
(*) Edit June 20202: although this cake always takes about 20 to 25 minutes to bake in my oven, many of you who have tried this recipe mentioned that the cake took longer to bake in their oven. As every oven is different, it is absolutely possible that this cake will need more than 25 minutes in yours! Make sure to check on the cake after 20/25 minutes and poke a skewer or a knife in the cake to see if it is baked or needs a little bit longer in the oven. For many of you, the cake took 35 to 40 minutes to bake instead of 20 to 25 minutes.