1. Line the base of a 20cm spring form cake tin with baking parchment.
2. Heat your oven to 190°C/Gas Mark 5. Place all the cake ingredients into a mixing bowl and beat with a wooden spoon until you have a smooth thick mixture. Pour into the prepared tin, smooth the top to level. Bake for 40 minutes until the cake is risen and when a skewer is inserted it comes out clean.
3. To make the syrup heat the sugar, water and orange juice. Bring to the boil then lower the heat and simmer for 3 minutes.
4. Remove the cake from the oven and place on a cooling rack. Pour over the hot syrup then scatter over the chopped pistachio nuts. Leave to cool before serving.