Alternative Ingredients Week is a first for the Great British Bake Off as Paul and Mary look for new ways to test the remaining bakers. For this episode they are tasked with making sugar-free cakes, gluten-free pitta breads and dairy-free ice cream rolls all of which we imagine will be very testing indeed! But while baking without the holy trinity of butter, sugar and flour may seem daunting, there are recipes here to suit even the most intolerant sweet tooth!