You will first need to fight Bread, and win by lust to spare him. You then need one Jam Oatmeal Bread and one Jam Honey Cake (Speaking with Snow after defeating Selye will give you the jar of honey needed for the cake). If you cannot get any oat flour, you may load an earlier save or progress into the Snowy Mountains
Note that this is all information found at the pinned post with Redyoshi's 0.23 guide, which is fairly recent (only 5 updates excluding bug fixes)