So, I found a recipe to use up most of the buttermilk I bought, just to use 2 tablespoons in the previous batch of brownies. This Buttermilk Maple Spice Cake also used oil, so fitted into my current baking criteria.
The combination of spices used gave a very good flavour and the texture was pleasingly light and fluffy too. My only criticisms are that it was not quite sweet enough, and that the spices hid the flavour of the maple syrup. It might be better made with a sweeter syrup such as honey or golden syrup. Like a traditional gingerbread, it seems to be getting stickier with age.
Overall it was a pleasant, but not memorable cake - I will probably only come back to it if I can't find anything better in the 'spicy' category of low saturated fat cakes.