1 Put the flour, sugar and almonds in a food processor and whizz at full speed for a few seconds. Add the butter and whizz again briefly; the mixture should resemble fine breadcrumbs. Add egg, lemon zest and vanilla essence, then whizz again briefly until the pastry forms into a ball.
2 Scrape contents onto a sheet of cling film, then either shape into a rough ball or roll into a cylinder shape, roughly 5 cm in diameter. Cut into flat discs or stars.
3 Wrap and chill the biscuit dough for at least 2 hours. You can also freeze it or make a few days ahead and keep in the fridge.
4 Bake in a preheated oven at 190 °C on a flat baking sheet.
Once baked and cooled, serve on the side of your affogatto.