Line a 20cm loose-bottomed cake or springform tin with non-stick baking paper.
Measure the butter and golden syrup into a heavy pan and heat gently until the butter has melted. Increase the heat and boil for about 3 minutes, stirring all the time. Remove from the heat and leave on one side to cool.
Place all the remaining ingredients in a large bowl and pour over the cooled sauce. Mix well until evenly coated.
Turn the mixture into the tin and leave to chill in the fridge for about 4 hours, until set. Turn out and cut into thin slices to serve.