Preheat the oven to 150°C

Sift the icing sugar together with the almond flour. Beat the egg whites until they form nearly stiff peaks. Gradually add the white sugar, and continue beating vigorously until all the sugar has dissolved and the egg whites form stiff peaks. Fold in the almond flour mixture and blend well until it is smooth. Spoon the mixture into a piping bag with a round nozzle and push the mixture down to the end.

Line a baking tray with a sheet of baking paper. Pipe around 60 rounds(with 2cm diameter) not the baking paper(they will flatten out to 3cm). Leave the rounds to dry for 30 minutes in a warm place. The mixture should now be dry to the touch.

Filling:beat the butter until soft. Gradually add the icing sugar and beat until you have an airy, smooth mixture. Add essence/food dye. Spoon the filling into a piping bag with a round nozzle.

Preheat the oven to 150°C and bake the macarons for 10-15 minutes. Leave the macarons for to cool on the baking paper before peeling them off.

Pipe a swirl of filing in one biscuit and put a second one on top. Press them together slightly, so that the filling just peeps out the sides. Can be stored in the fridge for up to a week.