Beat the egg whites until soft peak stage with an electric beater. Add the white sugar and beat until very thick, about 10 minutes. Preheat oven to 170 degrees C.
Fold in the almonds and icing sugar. Line baking trays with baking paper. Place the mixture in a piping bag and pipe 4cm flat circles on the baking paper.
Bake 10-12 minutes until firm but still pale. Cool before filling.