In baking, flaxseeds and chia seeds can replace eggs. In place of one egg, combine one tablespoon of ground flaxseeds or chia seeds with three tablespoons of hot water and let it sit until it gels.   You can also substitute mashed bananas for eggs in some cases. Vegans may substitute scrambled tofu for scrambled eggs. You can also use tofu in various egg-based recipes, including omelets, frittatas, and quiches.