Why Is My Egg Casserole Rubbery?
Your egg casserole may be rubbery if it is overcooked or cooked at too high of a temperature. The proteins in the eggs coagulate and become tough and rubbery when overcooked. To avoid a rubbery texture, try cooking the casserole at a lower temperature and keeping an eye on it to prevent overcooking. You may also want to consider using a higher ratio of dairy or other wet ingredients to the eggs to make them more tender.