Pre-heat the oven to 180°C/ 160°C fan assisted oven/ gas mark 4 and line and grease an 8 inch cake tin.
First make the pistachio paste by placing the pistachios in a food processor and blitzing until finely ground. Add the caster sugar, golden syrup, vanilla extract and egg white and blitz again until a paste has formed. Set aside for one moment.
Place the lemon zest in a food mixer along with the sugar and whisk for a minute together until fragrant.
Add the butter, one cube at a time and beat on high until light and fluffy.
Scrape the pistachio paste into the creamed butter and sugar and beat until combined.
Mix in the eggs, one at a time, scraping down after each addition.
In a separate bowl whisk together the flour, baking powder and salt. Add it to the rest of the batter until just combined.
Finally stir in the raspberries.
Pour into the cake tin, smoothing the top then bake for 60 minutes or until an inserted toothpick comes out clean.
Remove from the tin then leave to cool completely before icing.