Alfajores

We'll start by preparing the biscuit dough: place the sugar and diced, softened Virgilio butter in the bowl of a mixer and turn on; meanwhile separate the egg. Add the yolk to the mixture, and when incorporated, add the white. In a separate bowl place the sieved flour, potato starch and grated lemon zest. Stop the mixer, add the dry ingredients and use a spatula to combine; then turn on the mixer and beat for a couple of minutes to obtain a soft, even dough. Turn out onto a sheet of cling film and wrap carefully to form a block; leave to rest in the fridge for at least 2 hours. Now for the dulce de leche: place the milk and the split vanilla pod in a small pan, add the sugar and bicarbonate and heat gently, stirring with a wooden spoon. Bring to the boil, continuing to stir until the mixture darkens. Now use tongs to remove the vanilla pod and continue cooking the dulce de leche on a medium heat until the consistency is thick - this will take about an hour. When ready, pour into a bowl and allow to cool to room temperature. When the dough has rested, dust with flour and roll out to a thickness of 5 mm. Use a circular cutter (max 4 cm diameter) to cut discs; place these on an oven tray lined with baking paper. Bake in a pre-heated oven at 180°C for about 15 minutes. When cooked, cool on a rack, and then it's time to assemble the alfajores: spread dulce de leche on half the biscuits and top with the other halves. They're ready to serve for an afternoon snack with a cup of tea, or at breakfast to start the day with a smile