Preheat the oven to 325° F. Line a baking sheet with parchment paper.

In a food processor, combine the nuts, flaxseeds, and chia, and make 1-second-long pulses until the almonds are finely chopped to about the size of peppercorns — 15 to 20 pulses. Transfer to a mixing bowl with the pepitas, sunflower seeds, dates, salt, and psyllium husk powder, and stir well, making sure the psyllium is evenly distributed and the dates haven’t clomped together.

Measure the sweetener into a tall measuring glass, and then add enough water to hit 1 cup (¾ cup plus 2 tablespoons). Whisk to blend, then pour over the dry ingredients and stir well with a wooden spoon or spatula. Allow to thicken for 10 to 15 minutes, then scrape onto the prepared sheet pan.

With moistened hands, pat out into a wide rectangle. Switch to a mini-offset spatula, or a flexible silicone one, and spread the mixture out into a thin sheet that covers as much of the parchment as thoroughly and evenly you can. This will take a few minutes, but be diligent and patient — the thinner your crackers, the better, and any thin spots, particularly around the edges, will be prone to over-cooking. (You can also roll the dough out between sheets of parchment, but I have better results with the mini offset spatula.) Sprinkle all over with coarse or flaky salt.

Transfer to the oven and bake until dry to the touch and lightly browned, about 40 minutes, rotating the pan halfway through. Remove from the oven and cool for a minute or two, then carefully slide the whole sheet (parchment and crackers) onto a cutting board. Gently peel off the parchment (return it to the baking sheet) and with a chef’s knife or pizza cutter, cut into small square or rectangular crackers. Line an extra sheet pan with parchment and divide the crackers between the two pans, spacing them out a bit. Return to the oven.

Immediately reduce the temperature to 275° F and continue baking until the crackers are dried out — the bottoms should be firm and dry to the touch, 20 to 25 minutes more, rotating the pans halfway through. They may still seem a little soft right out of the oven, but will firm up as they cool. You can always test crispiness by removing one cracker after every 5 to 10 minutes, let it cool for 4-5 minutes, then break in half and taste. If they still seem too soft once cooled, return them to the oven and bake for 5 to 10 minutes more. Once cooled, transfer to an airtight container, in which they’ll keep for about 4 days.