280g cake flour
1 egg + 1 yolk
80ml seed oil
1/2 teaspoon baking powder
1 pinch of salt
Zest of 1 lemon
1 teaspoon vanilla extract
For the custard:
100ml moka coffee
100g corn starch
Prepare the shortbread: In a large mixing bowl combine the eggs, the lemon zest, the vanilla extract, the sugar and the seed oil. Whip vigorously to blend the ingredients. Sift together the flour, the baking powder and a pinch of salt then put them into the bowl and mix using your hands. Move the mixture on a working surface and work the dough until smooth and firm. Wrap in clingfilm and refrigerate for 1 hour.
Prepare the custard: make the coffee using a 4 cups moka or an espresso machine. In a little saucepan heat the milk and the coffee. Switch heat off before it comes to the boil.
Beat the eggs with the sugar and place into a large metal or heat resistant glass bowl. Add the corn starch and stir to combine the ingredients. Pour the hot milk over the egg yolks whisking vigorously.
Put the mixture back in a saucepan. Stir continuously over gentle heat until the mixture thickens (it will take about 8-10 minutes).
Switch off the heat and cover the custard with cling wrap. Allow to cool.
Pre-heat the oven to 175°C.
Take the dough out of the fridge.
Slightly dust the working surface with flour. Roll out until the dough is 3mm thick, then transfer to a greased round tart pan with removable bottom. Slightly press the dough onto the bottom and up the sides. Remove the excess dough.
Poke the bottom with a fork then pour the custard over the shortcrust.
Cut strips or discs (or any other shape you like) fom the remaining dough and decorate the crostata.
Bake to 175°C for 20 minutes on the lower part of the oven. Then move up to the centre and bake for 10 minutes more.