Substitution for Cake Flour:
Using all purpose flour (plain in UK) to make Cake Flour: For each cup of flour in a recipe, remove 2 Tablespoons of flour and replace with 2 Tablespoons cornstarch (cornflour in the UK). This recipe has 3 cups of flour so you will measure out 3 cups of all purpose flour, remove 6 Tablespoons and replace with 6 Tablespoons cornstarch, whisk to blend