Preheat the oven to 160°C fan/180°C/gas 4. Blitz the pistachios in a food processor, spice grinder or Nutribullet until very finely ground (but don’t over-blitz, or they’ll get oily). Beat the butter and caster sugar together until light and fluffy, then whisk in the eggs, one at a time.

Mix through the ground pistachios, flour, baking powder, milk and rose water, then divide the mixture equally between 12 paper cases in a cupcake tin – this will be about 2 heaped teaspoons per case.

Transfer the cakes to the oven and bake for 20 minutes, until well risen, golden brown and a skewer inserted into the middle comes out clean.

Cool on a wire rack, and meanwhile, mix your icing sugar and water together with a smudge of food colouring until you have a pale pistachio green. (I recommend Sugarflair Kiwi, but if you are using bottles, use a tiny bit of green and yellow.) Ice the cooled cakes and decorate with dried rose petals or wafer roses as preferred.

These will keep in an airtight container for 2–3 days.