Preheat the oven to 150C/300F/gas mark 2
Use a 23cm/9 inch square cake tin.
Line the base and sides of the cake tin with a double layer of greaseproof paper. Tie a thick band of brown paper around the outside of the tin and stand it on a pad of brown paper on a baking sheet. Sift flour and spice together. Cream butter, sugar and golden syrup together until light and fluffy. Add sour cream and mix well. Fold in flour, fruit and nuts until thoroughly mixed. Place in prepared tin, smooth the top. Bake for 3 to 4 hours, test with a warm knife after 3 hrs. Leave in tin for 20 minutes, then turn onto wire rack to cool.
