Preheat the oven to 190°C (170°C Fan, Gas Mark 5). Line a fairy cake tin with 14 Baking Cases.
Put the dates in a saucepan with 150ml (¼ pt) water. Bring to the boil, cover and simmer gently for about 5 minutes until soft and pulpy. Remove from the heat, stir in the treacle and mix well. Leave to cool.
Transfer the date mixture to a mixing bowl and mix in the egg, oil and milk. Sift the flour, Baking Powder and spices on top, adding any husks that remain in the sieve and carefully mix all the ingredients together until well blended.
Divide the mixture between the Baking Cases and bake in the oven for 15-18 minutes until risen, golden, and just firm to the touch. Transfer to a wire rack to cool. Store in an airtight container for 24 hours to allow the flavour and texture to develop.
To decorate, sift the icing sugar and 5ml (1 tsp) spice into a bowl and gradually mix in about 17.5ml (3 ½ tsp) warm water to make a smooth, spreadable icing.
Spread a little icing on to each cake and leave for a few minutes to set. Dust with a little extra mixed spice. Your cakes are now ready to serve and enjoy!
TIP: For an extra smooth sponge, purée the date mixture in a blender for a few seconds until smooth if preferred