Preheat oven to 350℉. Prepare a muffin tin with 12 muffin liners and set aside.

In a medium bowl, add ground flaxseeds and water. Give it a quick stir and let it sit for about 5 minutes until it gets a gel-like consistency.

Meanwhile, in a large bowl, add oat flour, rolled oats, almond meal, salt, and baking powder. Mix well.

To the flaxseed and water mixture, add maple syrup, lemon zest, lemon juice, mashed ripe banana, and vanilla extract. Mix well so that everything is combined.

Add the wet mixture into the dry mixture and mix well until everything is well combined. Next, add fresh blueberries and gently fold them into the mixture.

Fill each muffin liner ¾ of the way with the mixture. Place the muffin pan in the preheated oven for about 25 minutes, or until the muffins are cooked through.

Once done, take the muffin pan out of the oven and let it rest until the muffins reach room temperature.