1. Combine flour, wheat germ, flaxseed, oats, sugar, and salt in the bowl of a food processor. Pulse a few times to combine. Add butter, and pulse just until mixture is crumbly. Add peanut butter; pulse a few more times. Add milk; pulse until combined and mixture holds together.

2. Turn out dough onto a lightly floured surface; divide in half. Roll out each piece into a 1 1/2-by-6-inch log. Wrap logs tightly in plastic; freeze until firm, at least 45 minutes. Remove logs from freezer; wrap parchment or wax paper over plastic. Return to freezer until ready to bake.

3. Preheat oven to 350 degrees. Remove logs from freezer; let stand until slightly softened, about 5 minutes depending on how long they have been frozen. Using a serrated knife, slice log into 1/4-inch rounds. Place rounds on a baking sheet.

4. Bake until crackers just start to brown, about 12 minutes per side, turning once and rotating pan halfway through. Transfer to wire racks to cool. Store crackers in an airtight container at room temperature up to 7 days.