Add butter, golden syrup, black treacle, sugar, cinnamon & ginger to a small saucepan, warm on medium heat till dissolved & melted. ** Tip for using the syrup, treacle or molasses – spray oil on measuring spoon first & it will slip off easier. See Photo 1 from using Frylight cooking spray. Mix everything thoroughly before removing from the heat & placing to the side to cool. Grease & paper line your cake tin. See Photo 2 for how to use less paper, & fit better in the tin. Grease in place with butter, lining paste, or cooking/baking spray such as Frylight. Heat the oven to 180°c/160°c Fan Oven/350°f/Gas Mark 4.
Next add the eggs to a medium mixing bowl & whisk lightly to activate the protein & help provide structure for the cake. Add the milk & bicarbonate of soda (baking soda), whisking till all incorporated.
Add the cooled syrup mixture to this milky-egg mixture, stirring continually until all combined.
Lastly sieve the flour (& baking powder if using Plain/All Purpose Flour), over the mixture. Beat until combined & the batter is relatively smooth (few small lumps is fine) Use a hand-held or stand mixer for this if you like. Note batter will be thin & runny. See Photo 3.
Pour the cake batter into the prepared cake tin, & tap the tin on the counter/worktop a few times to expel any trapped air.
Bake in the centre of the oven, for about 25 - 30 minutes, until set, a deep golden colour, & a wooden cocktail stick comes out clean of crumbs. *If top is colouring too soon, cover in foil till cooked through. (Check & cover if needed, at some point after 15 minutes of baking.) See Photo 3 above.
Leave the cake in the tin, placed on a cooling rack for about 10 minutes. Then transfer the cake, paper & all, directly on to the cooling rack, & allow to cool.