First prepare the shortcrust pastry: work cold butter into cubes and sugar until you obtain a creamy consistency, then first incorporate the egg, then the orange peel and finally the flours and yeast.
Work until you obtain a homogeneous dough, then wrap with cling film and leave to rest in the fridge for 30 minutes.

Take the pastry and divide it into 2 pieces, roll out 2/3 of them and use them to line the edges and bottom of the mold lined with baking paper, then prick the bottom with the tines of a fork.
Sprinkle the bottom with the jam, then roll out the last piece and use it to cover the tart, sealing the edges well.

Prepare the royal dough: combine almond flour and egg whites in a bowl, then add the egg whites little by little, until you obtain a soft and sticky mixture (mine was a bit too soft and the decoration didn’t hold up).

Transfer the royal pastry into a piping bag with a star nozzle and use it to create decorative tufts over the entire surface of the tart.
Cook in a preheated fan oven at 180°C for about 45 minutes or until golden brown.

Let the tart cool completely, then mix the remaining 3-4 tablespoons of jam with the water and bring them to the boil in a saucepan, then brush them on the surface of the tart.

The delicious almond tart is ready, all you have to do is enjoy it.