Only my personal opinion - I wouldn’t. I tend to stay away from things with added sugar and salt. The added vitamins and minerals would also give me pause, I’m not sure that iron and zinc would be good additives for a bird. Although I’m not sure that there is enough in there to cause concern, I tend to stick to more natural treats. Pine nuts, seeds, bits of fruit, greens, etc is what I generally use.
Corn flakes ingredients: Corn (88%), sugar, salt, barley malt extract, vitamins (vitamin C, vitamin E, niacin, riboflavin, thiamin, folate), minerals (iron, zinc oxide).