I can’t get plain flour thanks to the current lockdown. Can I use self-raising instead in the Ginger And Walnut Carrot Cake? Do I omit baking powder and bicarbonate of soda? Will it change the consistency of the cake?
Nigella's Ginger And Walnut Carrot Cake (from AT MY TABLE) is made with a combination of plain (all-purpose) flour plus baking powder and bicarbonate of soda (baking soda). The ratio of leavening agents to flour in this particular recipe is lower than for self-raising flour so we would not particularly recommend using self-raising flour. If you do wish to try using self-raising flour and omitting the baking powder and bicarbonate of soda then bear in mind that it will change the texture of the cake slightly.
Nigella does have a Venetian Carrot Cake that is made with ground almonds (almond meal or almond flour) instead of wheat flour and we understand that for most people ground almonds are easier to find. Otherwise there are several baking recipes on Nigella.com that use self-raising flour. Just type "self-raising flour" into the "Find A Recipe" search bar.