Preheat oven to 350 F. Grease muffin pan with nonstick cooking spray and set aside.
In large bowl, combine barley flakes, baking powder, salt, and cinnamon, then set aside.
In a medium bowl, combine mashed banana, egg, melted butter, milk, honey and vanilla extract.
Pour wet ingredients over the dry ingredients and mix to combine. Gently stir in the blueberries.
Pour mixture into the muffin tin, filling each cup evenly. Bake for 23-25 minutes or until the cups are a golden brown. Remove from oven and let cool. Store in the refrigerator for 2-3 days in an airtight container or freeze for up to 1 month. Reheat and enjoy.