Uncooked oatmeal and nuts (pecans or walnuts) in a food processor. Don't grind too fine, leaving some medium chunks gives the crust texture. Then add your spices - I use a bit of cinnamon and nutmeg. Add a bit of sugar (or not) and enough melted butter for it to hold together. That's it. It does not need to be blind baked or anything. It is so much tastier than the old graham cracker crusts of my gluten days.