Preheat the oven to 150C/300F/gas mark 2
Use a deep 23cm/9 inch round cake tin.
Combine prunes, sultanas and currants in bowl, mix in grape juice and apple juice, cover, stand overnight. Grease and line the cake tin. Cream the butter and sugar in a small bowl with electric mixer until just combined. Add the sour cream and mix lightly. Transfer the mixture to large bowl. Stir in the combined coffee, water and jam, then the sifted dry ingredients in 2 lots. Drain the prune mixture, reserving the liquid. Add prune mixture, cherries, dates, peel and walnuts to the cake mixture. Mix well. Spread into the prepared tin. Bake for about 2 hours. Brush the reserved liquid over hot cake. Cover. Cool in the tin.
