Line a muffin pan with 15 parchment cupcake liners.
Preheat the oven to 350 F.
In a large mixing bowl, combine oats, oat flour, flax meal, cinnamon, and salt. Stir to combine.
Mash or puree the banana using a food processor or immersion blender.
Add the banana, brown rice syrup (see note), raisins, and chocolate chips (if using). Stir until thoroughly combined.
Note: Don’t substitute maple syrup for brown syrup; it’s not thick and sticky enough.
Using a cookie scoop, place 1/4 to 1/3 cup of the batter in each muffin cup. Use a spatula or your fingers to lightly pack in the mixture. (Dampen your fingers to make it easier.)
Bake for 20 minutes.
Remove and let cool in the pan for about 5 minutes, and then transfer to cooling rack.
Enjoy warm or cooled. Store in an airtight container in the fridge.