Step 1

Pulse nuts, pumpkin seeds, chia seeds, and flaxseeds in a food processor until the texture of very coarse sand (mixture should stick together when pinched). With motor running, drizzle in ¼ cup water, then oil and salt. Pulse until a wet dough forms. Scrape out onto a sheet of plastic wrap and form into a log. Roll up, using plastic to form dough into a tight 2" cylinder or square. Freeze until firm enough to slice, about 1 hour.

Step 2

Place a rack in middle of oven and preheat to 350°. Using a serrated knife, slice dough about ¼" thick and place on parchment-lined baking sheets, spacing ½" apart. Bake crackers until edges and bottoms are golden brown, 30–35 minutes. Let cool on baking sheet.

Step 3

Do Ahead: Dough can be made 1 day ahead; keep frozen. Crackers can be baked 4 days ahead; store airtight at room temperature.