Preheat the Oven: Preheat the oven to 350°F.
Make the Dough: Add the almond flour, water, ground flaxseed, and fine sea salt to a medium mixing bowl, then stir until the ingredients come together into a dough.
Prepare the Dough for Rolling: Place the dough on a sheet of parchment paper, then cover it with a second sheet of parchment.
Roll the Dough: Pat the dough down with your hands, then use a rolling pin to roll it into a thin layer about ⅛ inch thick, aiming for a roughly rectangular shape without worrying about making it perfectly even.
Add Flaked Sea Salt: Remove the top sheet of parchment and sprinkle a small amount of flaked sea salt over the dough, if using, then gently press the salt into the surface with your hands so it adheres.
Cut the Crackers: Use a pizza wheel or knife to cut the rolled dough into small squares about ½ to 1 inch in size, then use a toothpick to make a small hole in the center of each cracker if desired.
Transfer to the Baking Sheet: Carefully move the parchment containing the cut crackers onto a baking sheet, keeping the crackers in place.
Bake the Crackers: Bake for 20–25 minutes, or until the crackers are golden brown and crispy, keeping in mind that the pieces around the outer edges will brown faster than those in the center.
Finish Baking in Batches: Transfer crackers that have already turned golden brown to a cooling rack, then return the baking sheet to the oven to continue baking any crackers that need more time.
Cool Completely: Allow the crackers to cool completely on the baking sheet or on a cooling rack before serving.
Serve: Enjoy the crackers once they have cooled completely.
Store Leftovers: Transfer any remaining crackers to an airtight container or bag and keep them on the counter or in the pantry for about 4–5 days.