Requires: Stand mixer (alternatively, use electric beaters), 2 shallow baking trays and a rolling pin
Preheat the oven to 180°C conventional oven (350° Fahrenheit/Gas 4). Adjust the metal racks to the middle groove of the oven. Prepare 2 sheets of non-stick baking paper onto a work surface. Line 3 baking trays with baking paper.
Using a stand mixer or electric mixer, beat the butter, egg yolks, icing sugar (confectioners’ sugar) and yoghurt until combined. Use a wooden spoon to stir the flour, cornflour, salt, lemon zest and baking powder into the mixture, tablespoon by tablespoon until just combined. As the dough forms, you will need to use your hands. Transfer to a clean work bench and knead until smooth.
Note: 00 is a powder-fine Italian type of flour. It is made from soft wheat varieties, and is frequently used in Italian desserts and pastas. 00 flour is available in most supermarkets, Italian food stores and gourmet delicatessens.
Cover the dough with plastic wrap and refrigerate for minimum 30 minutes.
Remove the dough from the fridge. Divide the dough into 5 portions. Roll out 1 portion of dough into a circle with a diameter of about 22cm. Use a fluted pastry cutter to divide the circle into 8 wedges. Place a teaspoon of the blueberry jam (or jam of your choosing) toward the thicker side of each wedge.
Roll up the triangles of dough from the wide end to the pointed end. Place each biscuit on the prepared baking sheet. Repeat with the remaining portions of dough
Bake, one tray at a time in the middle groove of the oven for 15 minutes or until just golden and cooked through. Dust with icing sugar before serving – buon appetito.