Preheat oven to 375 degrees.
In small bowl, combine sugar and lemon zest for topping. Set aside.
Spray or line a muffin tin.
Whisk flour, baking powder, salt and poppy seeds in medium size bowl.
Add blueberries and fold into flour mixture to distribute evenly. Set aside.
In a large bowl combine sugar, flax eggs, coconut butter and vegetable oil. Mix until think and appears gelatin like.
Add vanilla, lemon juice and "buttermilk". Stir slowly.
Fold dry ingredients into wet mixture.
Mix until just combined. Be careful not to over mix.
Divide batter among muffin cups.
Sprinkle lemon sugar on top of muffins.
Bake for 20 minutes, or until muffins are golden brown.
Cool for 5-10 minutes before serving.
To make flax eggs: 1 flax egg equals 1 tablespoon ground flax seed + 2 1/2 tablespoons filtered water. Stir and let sit for 5-10 minutes.
To make dairy-free buttermilk: Whisk 1 cup non-dairy milk + juice from 1/2 lemon. Let sit for 10-15 minutes.