Put the Eggs, Sugar, Vanilla and Salt into a large bowl and start whisking at high speed while slowely adding the hot Water. Whisk for 10 - 15 minutes!
Preheat the oven to 175°C / 350°F (convection oven).
In a small bowl, mix the flour and starch. Then use a sieve to add it to the egg mix.
Carefully mix the flour-starch mix into the egg mass, folding it in by stirring from the bottom to the top while turning the bowl.
Prepare a baking pan with parchment paper and fill the batter into the baking pan.
Bake for about 15 to 20 minutes. Maybe more, depending on your oven.
Let the baked cake cool completely in the pan. Then, either cover it and let rest overnight or put it into the fridge for one hour before continuing.
Preparing the Filling
Strain the tangerines from the cans and keep 75ml of the juice.
Chose 13 of the best tangerines and set them aside for the decoration later.
In a small bowl, add some tablespoons of cold water and add the gelatin. Mix and let it soak.
In the meantime, put the Quark into a large mixing bowl. Add lemon zest from the lemon and also some juice of the lemon and the sugar. Mix it until the sugar is dissolved.
Heat the tangerine juice that you had set aside but don't heat it over 70°C /158°F!Add the soaked gelatine to the juice and mix it until it is dissolved.Now, add 2 tbsp. of the quark mixture to the gelatine, mix and add another tbsp. to it until the temperature of the gelatine is about the same as the quark.Next, add the entire gelatine mix to the Quark mixture and mix on high speed for 5 minutes.
Put it into the fridge for about 30 minutes.
Whip the cream until it can hold its shape.
Add the cream to the Quark and stir until it is mixed well.
Assemble the Cake
Cut the biscuit cake into two, using one half as the bottom of the cake by putting it onto a cake plate.
Put the cake ring around the cake, then fill some of the quark onto the biscuit.
Now place the remaining tangerines to the bottom (see video).
Add the remaining Quark mix on top.
Precut the other half of the cake into 12 triangular slices and place them on top of the cake as if it was one piece.
Put into the fridge for at least 5 hours, better overnight.
Decorate the Cheese-Cream Cake
Sprinkle a good amount of confectioners sugar on the top of the cake, then remove the cake ring.
Whip the 100 ml of cream and put it into a piping bag with a star tip.
Set cream decorations around the edge of the cake and add one of the tangerines that you have set aside on each precut top slice.
Put some cream decoration in the center of the cake and add a tangerine.
Optional: Sprinkle some chopped green pistachios on the cream to make the colors even pop more.
Keep cooled, serve cold. Also, this cake can be frozen very well but it takes time to thaw.