"These little ‘S’-shaped biscuits are traditionally made at Easter and are perfect for dunking in your milky coffee in the morning. They have a very subtle vanilla flavor with just the merest hint of lemon. Esse biscuits are particular to Venice but I have been unable to discover the significance of the letter S. The only explanation that has been offered is that Venice is known as La Serenissima – The Serene One, but this seems a little tenuous to me. If anyone has any clues, please let me know." — Norman Russell
Place the butter and sugar in a food processor and whizz to combine into a soft paste. Add the flour, egg yolks, vanilla extract, lemon zest and salt. Add 1 to 2 tablespoons of milk gradually, adding the full amount (or more) if the mixture is too dry to be pliant.
Place the mixture on a floured work surface and bring together. Wrap it up in clingfilm and place in the fridge for 1 hour.
Preheat the oven to 170° C. Cut off pieces of the chilled dough and roll into cylinders, 15 centimeters long and 2 centimeters in diameter. Bend into S-shapes and put onto a baking tray lined with parchment. Bake in the preheated oven for 10 to 15 minutes, or until only just golden.
Cool on a wire rack and store in an airtight container. They will keep for a good few days.