• START THE DAY BEFORE you want to bake the cupcakes.

To make the Vanilla Cupcake Mixture

• Split the vanilla bean length ways and scrape the seeds out into a bowl. Add the eggs and sugar and beat with an electric whisk until tripled in volume and the beaters leave a thick ribbon trail when you lift them out of the mixture.
• Sift the flour and baking powder into the bowl and whisk lightly. Add the melted butter and fold in gently with a large metal spoon.Fold in the chopped pistachios. Cover and refrigerate for 24 hours.
• Divide the mixture between the cupcake cases and bake in the preheated oven for about 15-20 minutes. Remove from the oven and allow to cool completely.

To make pistachio buttercream

• Put the butter sugar, milk, vanilla extract pistachio paste and Kirsch in a bowl and beat with an electric whisk or by hand with a wooden spoon until you get a light fluffy texture.
• Stir in drops of the food colouring until you get the desired shade of pistachio green, if you like.
• Fill the piping bag with the buttercream and pipe on top of the cold cupcakes. Balance a glace/candied cherry on top and sprinkle extra chopped pistachios around the edge.

To make your own pistachio paste

• Roast 125g/1 cup pistachios on a baking sheet in a a preheated oven at 160C (325F) Gas 3 for 10 minutes, taking care not to let them burn.
• Transfer to a bowl. Put 175ml/ 2/3 cup water and 60g/ 1/3 caster sugar in a saucepan and bring to the boil. When the sugar has dissolved and the liquid is boiling, cook over medium heat for 5 minutes.
• Carefully pour this syrup into a food processor with the roasted pistachios and 30g/ 1/3 cup ground almonds and pulse until you get a smooth paste.