Grease a 2lb loaf tin (900g) with greaseproof/parchment paper. This will not only stop it sticking, but also help you get the cake out later! I like to leave a bit of excess greaseproof paper so I can easily lift the cake out when it's cooled.
Preheat the oven to about 170C or 160C fan.
Place your black treacle, golden syrup, dark brown soft sugar and dairy free spread into a saucepan with 70ml of water. Gently heat and stir until completely melted. (Don't allow it to boil!)
Sift your flour, Xanthan gum and spices into a mixing bowl and then add your warm syrup/treacle mixture to it. Beat together using a wooden spoon until lovely and smooth,
Add half your beaten egg and mix thoroughly, then repeat with the other half.
In a small dish, add 2 tbsp of water to the bicarbonate of soda, mix until well combined and then add to your main bowl too. Mix once more. Your final mixture should now look nice and smooth, with a runny consistency.
Pour your mixture into the loaf tin and bake for 60 minutes. It should have a nice, dark exterior when it's done - but not a burnt one!!
Once baked allow to cool. The cake should be almost firm to touch, but will firm up more as it cools.
This is a cake best left to mature flavour wise for as long as you can manage. But I completely understand if you can't wait... maybe one cheeky slice straight away!
Enjoy!