Use a large baking tray and line with baking paper. Preheat the oven to 200°C. Chop almonds finely. Spread on a plate and set aside.
Place egg and sugar in a bowl and beat until pale and fluffy. Add remaining ingredients; stir well.
With moistened hands, shape the dough into 16 walnut-sized balls. Dip one side of each one into the reserved almonds. Place balls 2 cm apart, almond-side-up, on the baking tray.
Bake for 8–10 minutes until well risen and golden brown. Leave to cool on tray for 1 minute, then transfer to a wire rack to cool completely. Dust with a little icing sugar just before serving, if desired. Store in an air-tight jar or tin.