Sieve the icing sugar into a bowl. Add almonds, egg whites and baking oil and mix everything well together. Line 2 baking trays with baking paper. Form approx. 80 balls from the mixture with moistened hands. Turn half of the balls in sugar crystals. Spread the biscuits on the baking trays with some distance between them.
Leave the Amaretti in a cool place for a few hours, preferably overnight. Then bake one after the other in the preheated oven, bottom shelf (electric oven: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 20 minutes. Let the Amaretti cool down on the trays. Then carefully loosen and dust the biscuits with icing sugar. Store in tins cool and dry
Waiting time approx. 12 hours