The evening before, or at least 6 hours before, dissolve half of the yeast in warm water (roughly 150 ml) in a large bowl, add 50 g of flour and mix well until smooth. Cover with the rest of the flour for the first leavening (approx. 400 g), then cover the bowl with cling film and leave to rise. In the morning (or at least 6 hours later) the flour will have “cracks” in it, almost as though it burst, with the yeast coming out from underneath in rivulets. Put the raisins in warm water to soak for 10-15 minutes. Heat the oil in a heavy-bottomed frying pan, tip in the coarsely chopped walnuts (leaving a few half-kernels whole), the sugar and the raisins (squeezed to remove any excess water), stir and let everything cook a little. Combine the rest of the flour (400 g), the other half of the yeast dissolved in warm water (150 ml) and the Vin Santo, with the mixture that has already risen. Add the contents of the frying pan, continue mixing with your hands and season with the salt and pepper. Knead until the dough is smooth, then shape it into a round loaf and leave to rise for 2 hours, covered with cling film – it will double in size. Now knead the dough again for 5 minutes, and then divide it in half to form 2 loaves. Cut a cross on the surface of both of them using the tip of a sharp knife, and leave to rise for another 2 hours. Beat the egg yolk (or yolks if you think one isn’t enough) with the milk and brush the mixture over the surface of the “Pan co’ Santi”. Grease the bottom of a baking tray, place the 2 loaves on it (if they’re too big, you may need to bake twice) and cook in a preheated oven, at 180 °C, for 40 minutes. 

Pan co’ Santi has been prepared since ancient times, in Siena and its province, for about a month around All Saints’ Day. The “santi” (= saints) referred to in its name aren’t those in Paradise, but the walnuts, raisins, Vin Santo, olive oil and pepper, which make it rich and delicious. It goes well with Vin Santo, but since it’s peppery (if the recipe is genuine there’s a lot of pepper and you can taste it!) in Siena they recommend trying it with some aged Chianti.