Preheat oven to 400F.
Combine water, egg, honey, vanilla, and coconut oil in a bowl and mix thoroughly.
In a separate bowl combine flour, ground flax, baking powder, and salt.
Make a well and add the dry ingredients to the wet, mixing JUST until moistened.
Fold in blueberries; pour into greased muffin tins.
Bake for 15 minutes.