Glem Gas

Ingredients

Sponge cake:
5 eggs
110 g of flour 00
150 g of sugar
A pinch of salt
50 g of potato starch
1 vanilla bean or the zest of a lemon

Liqueur syrup:
200 ml of water
100 ml of rum
160 g of sugar

Custard:
8 egg yolks
150 g of sugar
1 vanilla bean
50 g of corn starch
1/2 lemon zest
500 ml of milk
280-300 ml of heavy cream
40 g of sugar

Preparation of the sponge cake

First of all, separate the egg yolks from the whites.
Add 50 g of sugar to the whites, and start whipping at medium speed. Don't beat the whites until stiff, but until they become shiny and stand in soft peaks. Add a pinch of salt.
Clean the whisks and take the yolks: whip the egg yolks with the remaining sugar (100 g) and add the flavoring you prefer (the zest of one lemon, 1 vanilla bean or an orange zest) to the mix.
When the mixture is creamy enough, add the yolks to the whites.
Mix and gently fold the ingredients in with upward movements from the bottom using a spatula: this will give you a soft sponge cake.
Sift and add the flour and the potato starch to the mix.
Fold these in with upward movements from the bottom as well.
Butter and flour the 24 cm diameter cake mold, and pour the mix in it.
Bake using the pastry cooking mode at 180°, on the lowest shelf, for 40 minutes.
Once cooked, allow the sponge cake to cool.

Preparation of the liqueur syrup
Bring to boil a mixture of water, rum and sugar in a small saucepan, then pour it into another bowl and let it cool. Once the syrup has cooled, store in the fridge.

Preparation of the custard 
First of all, pour the milk and the seeds of a vanilla bean in a small saucepan, then add the grated zest of half a lemon or, as an alternative, one big piece of lemon zest (whatever you like). Heat it all until it is almost boiling.
While the milk mixture is warming up, beat the yolks together with the sugar and the corn starch in a bowl. When the milk is almost boiling, remove from heat and take the vanilla bean pod out. Pour the milk through a sieve into the mixture of sugar, starch and eggs, stirring all well. Now, pour everything back into the saucepan and put over the heat,
stirring constantly until you obtain a dense and shiny cream. Once ready, remove the custard from the heat and allow it to cool.
After it has cooled, stir well and mix a spoon of heavy cream stirring vigorously. Then incorporate the remaining cream by moving the spatula from the bottom to the top.

Assembling the cake
Take the sponge cake and remove the outer crust. Then cut the layers. Repeat the operation for the second sponge cake too.
Spread the liqueur syrup over the sponge cake carefully and add a lot of custard; apply the second layer of sponge cake, spread the syrup again and cover with another layer of cream.
Repeat the operation for one more layer.
Now you'll see 3 layers completely filled and the remaining cream can be used to cover the whole cake.
Cut the remaining layers of sponge cake to dices and spread them over the top of the cake as a decoration. This is the typical decoration for a mimosa cake.