In a food processor, pulse the flax seeds and the rosemary.
In a bowl, mix all the dry ingredients - flour, yeast, flaxseed and rosemary, salt, paprika, black pepper, sesame seeds and nutritional yeast (optional).
Add the olive oil and incorporate well with a spoon, until you get a crumbly texture.
Add the water slowly and shape the dough with your hands until you get a loose ball of dough. If you need more water, add one tablespoon at a time. If it's too liquid, add more flour, also one tablespoon at a time. This will depend a lot on the flour mix you use, as some need more water than others.
Roll the dough with a rolling pin, between two sheets of parchment paper, until you get a thickness of about 0.1 inch | 3mm. The thinner you can make it, the crispier the crackers will be.
Place the extended dough in an oven tray, remove the top sheet and refrigerate while preheating the oven to 350ºF | 180ºC; about 10 minutes.
Remove the tray from the refrigerator and with a pizza cutter or knife, cut the dough in approximately 1 inch | 3cm squares (no need to separate them).
Place the crackers in the oven for 25-30 minutes, or until slightly golden brown (be careful not to burn).
Remove from the oven and let cool before separating them. As they cool, they will become harder and crunchier. Crackers are easily separated by hand.
Store in an air-tight container.