In a small bowl, stir together 2 Tbsp ground flax seed and 6 Tbsp water. Let sit 10–15 minutes, stirring occasionally, until thickened to the consistency of beaten eggs.
In a large mixing bowl, mash 2 ripe bananas until mostly smooth with a few small chunks remaining.
Add the thickened flax mixture, 1 tsp pure vanilla extract, 2 cups superfine almond flour, 2 Tbsp tapioca flour, 2 tsp ground cinnamon, and a pinch sea salt to the mashed bananas. Stir thoroughly until a very thick batter forms.
Preheat a large non-stick skillet over medium heat until hot (about 2–3 minutes).
For each pancake, scoop about 2–3 tablespoons of batter onto the hot skillet. Flatten each scoop gently into a 2½–3 inch disc using the back of the spoon (or lightly wet your hands or the spoon if the batter is too sticky).
Cook the pancakes 3–4 minutes on the first side, until the edges are set and the bottom is golden and releases easily from the pan. Flip and cook 2–4 minutes on the second side until cooked through. If needed, flip once more and cook an additional 1–2 minutes.
Transfer cooked pancakes to a plate and keep warm while you cook the remaining batter, repeating steps 5–6.
Serve the pancakes warm.