Matzoh is a product that’s been toasted, giving it distinctive flavor and texture. Regular matzoh meal is coarse, great for fillings and breading meat or vegetables. Matzoh cake meal is much finer and meant to be a substitute for flour, and works in cakes, cookies, and thickening sauces and soups. All-purpose flour is raw, smooth, and very fine, and while it is an adequate substitute for these latkes, that's not the case for every recipe.