For the lemon curd, mix the egg yolks with 225 g sugar in a bowl for several minutes with a whisk until the mixture becomes light and creamy. Add lemon juice and pour the mixture into a saucepan. Heat the mixture over medium heat, stirring with a wooden spoon until it thickens. With a whisk, whisk 120 g butter in pieces, add lemon zest and 1 pinch of salt. Stir 2 tsp. starch with a little water until smooth. Heat the cream until it boils up, stir in the starch and simmer gently for about 1 minute, stirring continuously. Pour into 3 glasses (approx. 250 ml each), close and let cool off
For the bases, grease 1 springform pan (24 cm Ø) and dust with flour. Mix flour, 120 g starch, baking powder, 300 g sugar and 3/4 tsp salt in a bowl. Add 180 g butter in small flakes to the flour mixture and grind with your fingertips to form small crumbs. Add 175 ml milk with the whisk of the hand mixer and stir for about 2 minutes. Whisk eggs, vanilla sugar and 60 ml milk, stir in gradually
Put half of the dough into the mould, the other half chill. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 25 minutes (stick test). Leave to cool for 10 minutes, remove from the tin and let cool on a cake rack. Clean the mould, grease it again and dust it with flour. Pour in the remaining dough and bake at the same temperature and for the same time. Let also cool down
Place the egg whites, 300 g sugar, 85 ml water and maple syrup in an ovenproof bowl. Place the bowl on a lightly boiling water bath. Whisk with the whisk of the hand mixer for about 7 minutes. Remove from the water bath and continue beating for a few more minutes until the mixture has cooled down. Spread a cake with about 1 1/2 glasses of Lemon Curd. Place the second cake on top. Spread the cake generously with the Frosting. Decorate with lemon zests if desired.
The rest of Lemon Curd keeps in the fridge for about 2 weeks
waiting time approx. 2 hours