Preheat the oven to 350 F. Line a muffins tin with 12 muffin papers and reserve.
In a large bowl, combine the whole wheat flour, baking soda, baking powder and salt, and whisk to mix.
In a medium bowl, stir the mashed banana, tahini and avocado oil until smooth. In a cup, stir almond milk, flax,and lemon. Let stand for 5 minutes for flax to thicken the liquids. Then, whisk into the banana mixture.
Stir the banana mixture into the flour mixture, just until combine, don't overmix. Stir in the crystallized ginger.
Scoop slightly rounded 1/3 cup portions of batter into each muffin cup. Divide any extra among the cups. Sprinkle tops with sugar in the raw.
Bake for 25 minutes, until a toothpick inserted into the center of a muffin comes out dry. Cool on racks.