Peel, core and slice up the apples. Pour water into a pot then add the apples, lemon peel, lemon juice, cinnamon and salt.
Place a lid on, bring it to boil. Reduce heat and cook apples until soft, for about 30 minutes. Remove the lemon peel then puree the apples with an immersion blender.
Melt butter or simply use vegetable oil. Add eggs and beat until light and fluffy. If the butter stays in lumps here and there, don't worry about.
Add the apple sauce and vanilla extract. Beat in salt, cinnamon and any optional ingredients like ginger, nutmeg and allspice. Allspice is highly recommended as it gives the cake a completely different character.
Beat in the flour in batches and finally the baking soda. It's important to add baking soda at the end, without delay pour the batter into a baking form then place it into the preheated oven, otherwise the cake won't raise.
Pour the batter into our favorite springform. In case our trust is waning in the nonstick coating, just line it with parchment paper.
Place the batter into the middle rack of a 360°F / 180°C preheated oven until golden brown spots start to appear on top, for about 30 minutes.
Whisk cream cheese until creamy. Add Greek yogurt, vanilla extract and sweetener of choice.
Level the top of the cake if necessary by cutting it off. Hide in a cozy corner and test if the cake will be okay with the cream. Adjust the flavor of the cream to complement the cake.
Spread the cream on top, possibly evenly. Keep the cake in the fridge until serving.