Almond Biscuits from Siena / Ricciarelli

Method

1. Put the almonds in a large owl with the sugar. Sift the baking powder with the flour into the almonds and sugar. With clean hands mix together thoroughly.
2. In an absolutely clean glass or metal bowl (free from any grease or dust) whisk the egg whites until stiff but not dry. Alternatively whisk the egg whites with an electric hand-held whisker. You can achieve good results in half the time it takes by hand. You should be able to turn the egg white upside down in a spoon without the mixture dropping. Then stir into the almond mixture. Add the almond and vanilla essence and blend until you have a soft malleable paste.
3. Pour some caster sugar onto a plate, enough to cover the plate in one layer. With clean hands roll heaped tablespoons of the mixture into small balls, roll in the sugar, and then press into the traditional oval or diamond shape by rolling into a fat sausage, tapering the ends, then flattening slightly with the palm of your hand.
4. Put the ricciarelli on a baking sheet lined with baking parchment, set well apart. If 1 tray is not enough, bake in 2 batches, keeping the remaining dough in the fridge while the first batch bakes. Bake in a preheated oven on the middle shelf at 200°C (400°F) Gas 6 for 10-12 minutes until lightly golden. Do not overbake or they will be too hard.
5. Remove to a wire rack to cool. Sift icing sugar over the biscuit tops and serve piled high on a plate.
6. Store in an airtight container or metal tin for up to 2 weeks.