Melt the butter and set aside. The butter shouldn’t get brown.
Mix flour, ground cinnamon (optional) and baking powder and set aside.
Clean, peel and trim the apples. Cut them into thin slices.
Adjust 2 layers of baking parchment crosswise in the baking tin.Preheat the oven to 160° C fan.
Mix sugar, vanilla sugar, salt and eggs with the electric handheld mixer (beaters) until foamy.Add melted butter … Add the flour … Add the cream … and mix.
Pour half of the batter in the baking tin and even the surface. Add 1 layer of apple slices.Pour the rest of the batter on top, even it. Add another layer of apple slices.
Put the baking tin in the oven for about 35 min. Make the famous test with the wooden pin … If you think it’s not ready add another 5-10 min.
After about 10 min you may lift the cake out of the baking tin with help of the baking parchment. Let the cake cool down to room temperature on a cooling rack before removing the baking parchment.