Graham crackers (aka Graham wafers) are flat, crisp wafers made from graham flour and sweetened, often with honey.
They are considered a sweet biscuit rather than a savoury biscuit or cracker.
You can buy the crackers already ground into 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 Wafer Crumbs
– © Denzil Green
Digestive biscuits. Not the same thing (less sweet), but will do the same job and taste basically the same once ground up and used for pie crusts, cake bases, etc.
14 to 15 squares = 1 cup of crumbs = 100g / 3 1/2 oz
Freeze in freezer bags for up to 1 year.
They were created by Sylvester Graham (1794–1851) in the 1830s. It is ironic that what he intended to be a glum, healthful food is now basically used as a cookie and for desserts.
See Graham Flour for more history.