Sieve the flour with a pinch of salt, then pile it up on a wooden pastry board or your work surface and create a “well” in it. In the centre put the softened butter (you should take it out of the fridge half an hour beforehand), the egg yolks, sugar and grated lemon peel. Mix the ingredients together delicately, first with a fork and then with your hands (if possible cold). Work the dough quickly to form a smooth, elastic ball of dough; sprinkle lightly with flour, put it in a bowl, cover with a tea cloth and leave to “rest” in a cool place for two hours.

Mix the ricotta with the sugar and leave to rest for about an hour; then wrap it in a cloth and squeeze out as much water as possible. Peel the pears, cut them in half and remove the cores.  Then cut them into small cubes and add the grated lemon rind. In a bowl, mix the ricotta with the pieces of pear and the vanillin. Line a well buttered cake tin with ⅔ of the pastry dough (using a little flour to help); flatten it out well with your hands and create an edge about 2.5 cm tall all around Prick the bottom of the pastry all over with a fork and pour in the ricotta and pear mixture. Cover with the remaining pastry, sealing the tart well all around the edge. Bake in a preheated oven, at 180 °C, for approximately 30 minutes. Remove the tart from the oven and leave it to cool down well. Sprinkle this mouth-watering treat with icing sugar and serve!