Preheat the oven to 160°C (355°F) for a fan oven or 180°C for a conventional oven. Prepare two 20cm (8-inch) round cake tins by greasing with butter and lining with parchment paper.

In a mixing bowl, combine softened unsalted butter and golden caster sugar. Beat on medium speed for 3–5 minutes until fluffy and pale.

Add the vanilla extract and eggs one at a time, mixing on low speed until fully combined.

Sift together plain flour, baking powder, and sea salt. Finely grind the pistachios and fold into the wet ingredients gently.

Divide the batter between the prepared tins and smooth the tops. Bake for approximately 35 minutes or until a toothpick inserted comes out clean.

For the buttercream, cream softened butter until pale. Gradually add sifted icing sugar, then add pistachio cream, sea salt, and lemon juice.

Once layers have cooled, place one layer on a plate. Spread half the buttercream, then add raspberry jam. Top with second layer and frost the sides and top.

Decorate with fresh raspberries, chopped pistachios, and fresh mint sprigs.