There's a low-carb group on Facebook and on there, DJFoodie posts recipes every now and then. And, lo and behold, DJFoodie to the rescue with a crunchy cracker recipe that uses parmesan cheese and nut flour.
I only have almond flour available, and all of the other ingredients already in the house, so I went with a pure almond flour version (if I'd had hazelnuts, I might have ground them in the blender and used them too, but I didn't have any). I suspect the better crunch finish from the hazelnuts is due to the higher proportion of fat in those nuts.
Anyhoo... here's how they went:-
2. Combine ingredients in a mini-chopper or food processor, and mix until a ball of dough has formed or, until it's all smeared up the sides of the chopper bowl but well mixed.
3. Place the dough on a greased sheet of parchment paper or foil.
4. Place another sheet above it, and roll out the dough so that it forms a single thin sheet of dough.
5. Remove the top sheet. Where it's not rectangular, cut bits off the dough and stick bits on so it's roughly rectangular and smooth with a spatula or palette knife. It's pretty soft and squidgy, so you can just push any lumps or cracks together.
4. Use a pizza cutter (or just a chopping knife) cut through the dough to form 48 little rectangles. If you want precision, measure it first and mark along the edges where to cut.
5. Place the parchment or foil on a thin baking tray.
6. Bake for roughly 45 minutes, but start checking at 30 minutes. It will probably crisp around the edges first. You want the cheese to melt in the mixture and then you want any moisture to burn off. The cracker will darken and firm up. When the sheet is the same even slightly darker color, across the enter sheet (the edges and the center are all the same color), remove the sheet from the oven.
7. Let the sheet cool completely, then pick up the crackers and break where you made the cuts.
8. Serve with dip, cheese, pate etc.
Now, I think the ones I made are too thick and they're more biscuits than crackers, but they are beautifully crispy. DJFoodie cuts the mix into 48 servings, compared with my 24. So, perhaps using 2x baking sheets and rolling it a lot thinner would be better. And maybe gruyere rather than parmesan, so they're a bit less strongly flavoured.