Preheat oven to 375 degrees F (190 C) and line a standard muffin tin with paper baking cups. (I find the unbleached, brown paper liners to work best – they don’t stick to the muffins when peeling.)
In a large mixing bowl, prepare the flax egg by mixing flaxseed meal and water together. Wait 5 minutes. Then add banana, baking powder, and baking soda and mash until only small chunks remain.
Add vanilla, oil, coconut sugar, brown sugar, maple syrup, sea salt, and cinnamon (optional) and whisk vigorously to combine. Add almond milk and whisk once more to combine.
Add almond meal, gluten-free flour blend, and oats and stir until just combined. Then divide batter between muffin tins, filling all the way full - there should be 12 muffins (amount as original recipe is written // adjust if altering batch size).
Top with walnuts (optional). In place of walnuts, you can also substitute more rolled oats and/or a sprinkle of organic cane sugar.
Bake for 28-35 minutes or until a toothpick inserted into the center of a muffin comes out clean and the edges are dark golden brown. Remove from oven and let cool in the tin for 5 minutes. Then remove from tin and let cool completely on a cooling rack. The wrappers peel away easier and the muffin texture is best when completely cooled.
Serve with vegan butter, nut butter, or as is. Store leftovers in a covered container for up to 4 days or in the freezer up to 1 month.