Matzo (also known as matzah or matza) is traditional Jewish flatbread that is unleavened, yielding a cracker-like texture. It's an essential part of Passover–as Jewish Law forbids leavened bread during this festival, matzo is used as breadcrumbs and to make matzo balls for soup. One thing to keep in mind: if you keep Kosher, the time between adding liquid to the dry ingredients to placing the matzo in the oven must be no longer than 18 minutes, to eliminate the possibility of fermentation.
Preheat oven to 500°F. Premeasure a piece of parchment paper to fit a large sheet pan. Have plastic wrap and rolling pin ready for rolling the dough.
Measure oat flour and salt into a mixing bowl. Set your timer to 18 minutes, then pour ¼ cup water into oat mixture and stir quickly to combine, adding more water if needed to make a workable dough. Place dough on the parchment paper, cover with plastic wrap and quickly roll ⅛-inch thick. Poke dough all over with a fork, then bake for 10-13 minutes, or until crisp and slightly browned on the edges.