Preheat oven to 350°.
Start by making the flax eggs: stir flaxseed meal and water together then set aside for 5-10 minutes or until the flaxseed has absorbed the water.
Next, use a fork to mash the bananas into the bottom of a bowl.
In a separate bowl, cream butter and sugar together; then, add the bananas, vanilla and flax eggs.
Add the flour, baking powder, baking soda, cinnamon, and salt to the same bowl and stir to combine, then stir in the chopped walnuts.
Grease a bread pan with coconut oil, then pour batter into the pan and bake bread for 45-50 minutes or until a toothpick comes out clean. Wait 10 minutes before running a knife along the edges, then carefully inverting the bread onto a cooling rack. Wait until bread cools completely before slicing.