In a mixing bowl, add ground flaxseed, onion powder, garlic powder, salt, sesame seeds -if used, and dried rosemary.
Give a good stir to combine, then pour the water.
Use a spatula to combine all the ingredients at first, then use your hands to form a ball of dough. The more you knead the dough, the drier and harder it will get. If the ball really sticks to your hands - can happen when your ground flaxseed is thicker than mine - sprinkle extra flaxseed to slightly dry the ball and make it easy to roll.
Place the dough ball onto two pieces of parchment paper, and use a rolling pin to roll about 2-4 mm thick - I like my crackers thick!
Use a pizza cutter or knife to cut the rolled dough into squares/rectangles. I usually shape a large rectangle and then cut smaller squares inside. I keep the leftover dough from the border to reform a ball, roll again, and cut more crackers with this dough. You should make about 30 square crackers in total.
Leave the crackers onto the piece of parchment paper and slide the piece of paper onto a baking sheet. Prick each cracker with a fork 2-3 times.
Bake at 350F (180 C) for 20-25 minutes. I recommend checking the crackers every 5 minutes after the first 15 minutes of baking. This will prevent over baking the crackers. If yours are rolled thinner, they will bake faster and get crispier, more like tortillas chips. You know it is ready when the border and center are crispy and golden brown. If soft in the center, keep baking - they don't get much crispier when cooling down.
Cool down on a cooling rack and enjoy at room temperature with your favorite dips.
Store in an airtight container for up to 3 weeks in the pantry.
Sesame seeds: I love them, but you can use any other seed you like or even make plain crackers. The recipe will also work well without the sesame seeds.Baking time: it depends on the thickness of your crackers. The thicker, the longer you have to bake them to get crispy! Flax seeds: use golden or brown flaxseed. The golden flaxseed has less flavor than brown. You can grind your own flaxseed or use store-bought ground flaxseed. Herbs: if you don't like rosemary, other herbs that are tasty will be dried oregano or dried thyme, or a combo.