Preheat oven to 400 degrees F.

In a food processor or blender, blend the almonds until they form a coarse flour. Add oats (and flaxseed if you're using whole flaxseed) and blend a bit more until they are pretty broken up. Pour into a mixing bowl or bowl of a stand mixer.

Add the remaining ingredients except for the butter and milk and combine. Add the butter chunks and mix until well incorporated. With the mixer running, pour in the milk. Let the mixer run until the dough starts clumping up (kind of like if you were making the crumble topping for an apple crisp).

Dump the dough onto a clean surface, pat it into a rectangle, and roll out to a 1/4 inch thickness.

Cut the dough with cookie cutters (or just use a pizza cutter to cut it into squares. Lay them on a greased or parchment-covered cookie sheet. They don't expand really at all, so you can put them quite close together (I can do about two dozen on a single sheet).

Pat remaining dough back together, re-roll and repeat.

Bake for 12 minutes. Let cool for a few minutes on baking sheet before eating.