For the shortbread

1. Take the kitchen robot with dough hook.
2. Mix the flour together with the Zùsto.
3. Now add the butter along with the egg yolk and a pinch of salt.
4. Mix everything well to form a ball.
5. Let this rest in the fridge for 2h.
6. Heat the oven to 180 degrees.
7. Butter the baking pan and dust with flour if necessary.
8. Now roll out the shortbread dough and line the baking pan with it.
9. Bake for 20 minutes.

For the lemon cream

1. Soak the gelatine sheets in water.
2. Let the lemon juice boil down gently with 40 g of Zùsto. Add the butter and, once melted, pass the mixture through a sieve and gently reheat. 
3. Beat the eggs, 30 g of Zùsto and the pudding powder until fluffy with a whisk.
4. Now add the lemon mixture.
5. Stir well and heat to max 85 degrees.
6. Remove the pot from the hob and add the soaked gelatine. 
7. You may pour this mixture over the cooled shortbread and let it set in the refrigerator. 

Making meringue for the finishing touch

1.  Beat the egg whites with 15g Zùsto until smooth.
2. In a saucepan, bring the water and 50g Zùsto to a boil until 170 degrees.
3. Very carefully add this to the egg whites and beat the mixture lukewarm/cold.
4. Put the mixture in the piping bag and pipe tufts on the cooled cake.

Enjoy!