1 cup caster sugar
170g butter, softened
zest + juice 1 lemon
1/4 cup pistachios
1 3/4 cups flour
leaves from 4 sprigs fresh mint
LEMON BUTTER CREAM
125g unsalted butter
4 cups icing sugar, sifted twice
2 tbsp milk
juice 1 lemon
2 cups icing sugar, sifted
juice 1/2 lemon
handful extra pistachios, finely chopped
Place butter into the bowl of a stand mixer and beat for 10 - 12 minutes until really light and fluffy, turn speed down and, using a large spoon, add the twice sifted icing sugar into the butter spoon-by-spoon until well incorporated. Continue to beat for a further 10-12 minutes. I find the longer you beat butter cream the better and lighter it will be. The results are worth the time and patience.
Add the lemon juice and milk and whip a little more to combine.
Remove butter cream from bowl and transfer into a piping bag fitted with a star-shape nozzle. Set aside.
Pre-heat oven to 180˚C/350˚F, line 2 baking trays with non-stick baking paper.
Cream butter and sugar together for about 10 minutes in a food processor until well combined.
Add egg and continue to beat until well incorporated, then add the lemon zest, pistachios and mint leaves, whizz until mint is super finely chopped then add the flour, beat until you get a soft cookie dough.
Cover dough in cling wrap and chill for 30 minutes before turning dough out onto a lightly floured clean surface and kneading lightly. Roll dough between clean palms into small walnut and equally-sized individual balls, place on a pre-lined baking tray and flatten tops of cookies lightly with the bottom of
Bake cookies in the pre-heated oven for 25 - 30 minutes until crisp and cooked through. Remove and allow to cool on wire racks.
Mix icing sugar and lemon juice until smooth and creamy - add more lemon juice or icing sugar to get a runny consistency if required.
To assemble, pipe butter cream onto the flat side of one cookie piece, top with and sandwich together with a second cookie half.
Arrange all sandwiched cookies on a large wire rack with baking paper laid underneath then drizzle the lemon icing over the cookies. Sprinkle tops with crushed pistachios when the icing is half set (if you do this too soon, the nuts will just slide off the icing!). Serve chilled.