Preheat the oven to 180°(350°F) Gas mark 4

Place the dates in a bowl with the butter & bicarbonate of soda. Pour over the boiling water and stir until the butter has melted. Set aside to cool

Place the sugar & eggs in a large bowl and beat well to combine.

Add the cooled date mixture

Sift in rhe flour, baking powder, mixed spice and salt.

Add the walnuts and stir all the ingredients until thoroughly mixed.

Pour the mixture into a lightly greased 18 cm round deep cake tin linwd with baking parchment

Level the top and cook for 1 -11/4 hours or until the cake has risen and nicely browned and a skewer inserted in the middle comes out clean

Turn out onto a wire rack and leave to cool

The cake can be kept wrapped in foil or in an airtight container for up to 5 days