Where North American recipes will often turn to Graham cracker crumbs to use as a base for pies and cakes, recipes in the UK, Australia and New Zealand will call instead for Digestive Biscuit Crumbs.
To make crumbs, whiz in food processor or place between two sheets of waxed-paper or put in freezer bag and crush by rolling a rolling pin over them
Graham Cracker Crumbs. Not the same thing, and sweeter, but will do just as nice a job for pie crusts, cake bases, etc.
5 Digestive Biscuits = 2 ½ oz = 75 g = ⅔ cup crumbs
7 – 8 Digestive Biscuits = 3 ½ oz = 100 g = 1 cup crumbs