It's the quarter-final and Mary Berry and Paul Hollywood test how the five remaining contestants cope with unconventional flours and unusual desserts, beginning by baking a signature loaf using non-traditional flours such as spelt, rye, potato and tapioca. In the technical challenge they each have to prepare a gluten-free dacquoise, which is made with meringue, coffee custard and hazelnut praline, before creating dairy-free novelty vegetable cakes for the showstopper round. Mel Giedroyc and Sue Perkins present.