As a chemistry teacher, I am acutely aware. This is why I suggested that the only "thing" you could measure for flour would be "granules", the leftover ground bits which make up the substance of the flour. However, a mole of granules would still be insanely large (because you'd have to have 600 sextillion particles of flour, which would take up an insane amount of space) and a mole of any chemical constituent like amylose would be impure, and thus the measure meaningless. The greatest problem still lies in the counting, which would require either nigh-infinite time, or would require a conversion from either mass or volume into moles, so the whole point of using moles becomes moot.