Whether you follow a plant-based diet or not, a flax “egg” can be a great substitute to use when baking. It’s handy to know in a pinch if you run out of eggs and it’s also a great way to work extra fiber and Omega-3’s into baked goods.
Flax “Egg”
Equals one egg
1 tbsp ground flax
3 tbsp water
Mix ground flax with water in a small bowl. Allow to stand for several minutes to thicken. Use in a baking recipe as you would an egg.
The flax egg works well in hearty baked goods like banana bread or zucchini bread. I would not recommend using it in lighter or more delicate baked goods such as cakes.
Everything Is Homemade 
I use flax eggs all the time! I find they are better for cookies and brownies, but I use 1/4 cup applesauce in my quick breads, or cakes.