Preheat the oven to 160°C Fan/180°C conventional oven/355°F and grease and line 2 x 20cm loose-based round cake tins with non-stick baking paper. Set aside.

In a large bowl, cream together the butter and sugar for about 3-5 minutes until lighter in color and smooth. Add the vanilla extract and mix again.

Add the eggs one at a time, whisking until the batter is smooth.

In a food processor, grind the pistachios into a fine crumb.

Sift in the flour and baking powder, then add the salt and ground pistachios. Fold in until just combined.

Divide the batter equally between the two prepared tins and smooth the surface.

Bake for about 35 minutes, or until a skewer inserted into the center comes out clean. Cool in the tins for 15 minutes before turning out onto a wire rack to cool completely.

For the buttercream, cream together the softened unsalted butter and sifted icing sugar until pale and increased in size. Add the pistachio cream, salt, and lemon juice and beat again.

Once the cakes have cooled, place one on a flat plate and pipe half the buttercream on top in an even layer. Spread the raspberry jam on top, then add the second cake followed by the remaining buttercream.

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