Simmer drained wheat with milk and lemon zest for 3-4 hours.
Stir in cinnamon, vanilla sugar, and orange zest, then chill overnight.
Beat sugar, butter, and eggs, then mix in flour to form a smooth pastry.
Chill the pastry in a cool place for one hour.
Preheat your oven to 190°C.
Combine the wheat mixture with lemon, cinnamon, vanilla sugar, and orange zest.
Mix ricotta with egg yolks, orange flower water, and candied peel pieces.
Whisk egg whites with sugar and fold into the ricotta mixture.
Grease a 35cm flan tin with butter.
Line the tin with two-thirds of the rolled-out pastry.
Fill the pastry case with ricotta mixture and top with pastry strips in a lattice.
Bake for 45 minutes, cool, and dust with icing sugar.