Preheat the oven to 375°.
Combine the dry ingredients in a large mixing bowl. In a separate bowl, whisk together the egg and apple cider vinegar.
Add the melted butter and whisk to combine.
Add the wet ingredients to the dry ingredients and mix until the dough resembles a very course meal.
Add the water by the tablespoon until the dough comes together without crumbling when pressed.
Cut the dough in half and roll out one portion between two sheets of parchment paper to an even thickness of ⅛-inch.
Store the other half of the dough in the refrigerator for up to one week or in the freezer for up to three months.
Remove the top piece of parchment paper and use a pizza cutter or knife to slice the crackers into squares, rectangles or any shape desired.
Poke holes in each cracker with the tines of a fork.
Slide the parchment paper with the prepared crackers onto a pizza stone or baking sheet and bake for 25 to 28 minutes.
Allow the crackers to cool, break apart and store in a mason jar or other airtight container.