Do not open the door while baking, will need a full hour in oven, maybe 5-10 minutes more. The cake is best left at least a day or two before eating when it get super sticky and rich. Keep covered in a container in the fridge after day 3, keep for up to a week.
Butter and line a 23cm square baking tin or shallow roasting tin 20x30cm in size. Heat oven 160C (140C fan) gas mark 3.
Put the butter, sugar, coffee and treacle into a saucepan and heat gently for about 5-10 minutes until melted. Stir in the milk and allow to cool until just warm.
Beat the eggs together and add to the melted sugar/treacle/butter mix.
In a large bowl, add all the dry ingrediens - spices, flour and soda. Chop the ginger into small pieces and add to the dry ingredients, add the grated orange zest. Mix together and make a well in the centre.
Gradually pour in the liquid (butter/treacle mix) that should be warm not hot and slowly incorporate into the dry ingredients until thoroughly combined, it should resemble batter.
Pour into prepared tin and place in the centre shelf of the oven and bake for an hour. DO NOT OPEN OVEN DOOR UNTIL AN HOUR, test with a skewer, if it comes out clean, the cake is done. If it needs any longer, just five minutes at a time should be enough but as long as skewer comes out clean.
Allow to cool in tin for an hour. Turn out on to a wire rack to cool completely. When completely cold, wrap in foil and leave for a day or two at least. Cut into brownie size squares and transfer to a container. Enjoy with a steaming cup of tea preferably in front of a roaring fire!!!