Preheat oven to 350F and prepare a muffin pan by spraying with cooking spray. Set aside.
Place oats and chia into a food processor and grind into a flour. Add baking soda, cinnamon, and salt and gently pulse.
In a medium bowl, add almond butter, mashed banana, maple syrup, egg, and vanilla and mix well.
Slowly incorporate dry ingredients until batter is smooth.
Fold in raisins, chocolate chips, and/or walnuts if using.
Pour batter into prepared muffin pan, filling each cavity until it is about ¾ full. Bake for 15 minutes, or until the tops of your muffins are set and a toothpick inserted into the middle comes out clean. Allow muffins to cool in pan for 10 minutes before removing. Store in an air-tight container for up to a week.
Recipe by Three Hungry Boys at https://www.threehungryboys.com/2021/01/27/banana-oat-muffins-gluten-free/