In a small bowl, whisk together the ground flax seed and water to make a flax egg. Allow this mixture to sit and thicken while you’re preparing the rest of the recipe, about 5 to 8 minutes.
In a mixing bowl, stir together the flour, baking powder, cinnamon, and salt.
In a separate bowl, whisk the mashed bananas, almond milk, maple syrup, and vanilla extract together.
Add the flax mixture (flax egg) to the wet mixture and whisk to incorporate, then pour the wet mixture into the bowl with the dry mixture and stir to combine.
Heat a pancake griddle or skillet to just above medium heat. Add enough oil to coat the surface.
Measure about ⅛ cup of batter and pour it onto the hot griddle/skillet until you run out of room, being careful not to crowd your pancakes. Cook until several bubbles rise to the top of the pancake and the sides firm up.
Flip the pancakes and continue cooking until they're cooked through, another minute or two.
Repeat for remaining batter. Serve with sliced bananas, pure maple syrup, nut butters, jam, or your favorite pancake toppings.
Just about any gluten-free all-purpose flour will work for this recipe, but use brands (such as King Arthur) that do not contain xanthan gum.