Something to think about when preparing for Shabbos
I would suggest that it can also be read as cooking the whole amount and leaving cooked mann for Shabbos. It is a mitzvah to honor the Shabbos by cooking and baking for special foods to be enjoyed at the festive meals we set out each during the evening and the day. So even though they could have just eaten the mann in the state in which it fell from the skies, they would take the trouble of cooking and baking it to have the mitzvah of preparing for Shabbos. I mentioned the fact that there is merit in preparing things oneself rather than just "buying Shabbos" -- that is leaving all the cooking ot the takeout plac. We learn this from Tananim who would make a point of doing work personally in order to prepare for Shabbos. They did not consider themeselves too important or too busy to do "menial" chores that were in honor of the day. BTW, lest you think this is someonthing that only concerns women, pay attention to the grammatical construction of the verbs in the statement; they are written in the general plural -- not the feminine form.