What is the correct substitution for the self-rising flour called for in Nigella's baking recipes? Are both baking powder and salt added to regular all-purpose flour or just the baking powder? Is baking soda added as well? What should I use as a recipe, to substitute for all-purpose flour?
For Nigella's recipes where she suggests using self-rising flour then you can instead add 2 teaspoons of baking powder to each cup (150g) of all-purpose (plain flour). We would not add baking soda (bicarbonate of soda) unless the recipe states specifically that it is added separately to the self-rising flour.
Nigella's recipes come from the UK where self-rising flour (known as self-raising in the UK) does not have salt added so we would not add salt to the self-rising flour substitute. However we appreciate that in the US self-rising flour does contain added salt as it is mainy used for biscuits. So if you are looking to replace self-rising flour in a US recipe then you need to add 2 teaspoons of baking powder and 1/2 teaspoon salt to every cup of all-purpose flour.