If I use regular flour how much baking powderv

For every cup of regular flour, add in 1 1/2 teaspoons of baking powder and a goodly pinch of salt, about 1/4 teaspoon at the most - if you wanted to add the salt. For this particular recipe, you could measure out the 100 grams of flour and add in 1 teaspoon of baking powder and the pinch of salt if you wish. In the case of this recipe, I would omit the salt because the cheese will be bringing along plenty, and you can dust the tops with coarse salt as well. American self rising flour contains salt, whereas British versions do not. I actually prefer not to add in in myself either, because it is generally a separate ingredient in most recipes anyway and you don't need the extra.