I was looking at a British recipe that called for "medium or rough oatcakes, finely crushed" to make a crumb crust. What would be the American equivalent in this case?
Sounds like it's headed for an oatmeal-crumb crust.
You might try a granola bar, or oatmeal cookies that are hard and mostly oatmeal.
are a flat, round cracker made almost entirely of coarsely ground oats (oatmeal in the Scottish/English sense). Their 'fine' ones use a finer grind. These are not sweetened, but there are recipes for a sweetened oatcake.
I have made this style of oatcake using oat flour and rolled oats that I ground in a spice grinder. Bobs Red Mill also sells a 'Scottish oat meal' that has, I believe, the right texture.
One possibility is to grind rolled oats and then toast them in the oven or a skillet. Or toast and then grind.
Ground granola or oat cookies might work, but probably gives something sweeter. Is there sugar in the crust recipe?
By the way, the English equivalent to the American granola bar is a 'flapjack'
Flapjack? Interesting. Who knew?
This is a crust for a savory cheesecake so I don't think the extra sweetness would be appropriate. I'm thinking that I might just sub out a nut-based crust or a breadcrumb crust so that there's one less step to deal with in making oatcakes or trying to locate them in my area.
Ground toasted oats and flour would be closer to a British oatcake than granola. There is very little sweetener if any. They are closer to a cracker than a cookie.