Rose water and pistachios have a subtle affinity, and are used in this recipe to flavour a rich buttercream frosting. The green colour of the topping gives them an unusual appearance.
Preheat the oven to 180°C/350°F/Gas 4. Line 8–9 cups of a bun tin (pan) with paper cases. Beat together the butter and sugar until light and creamy. Add the vanilla.
Gradually add the eggs, beating well after each addition. Add the flour and fold it in