Preheat oven to 350 degrees and prepare 12-cup muffin tin with non-stick spray or silicone baking cups.
In a large bowl, whisk together the brown sugar and eggs.
Add the mashed banana, vanilla extract, greek yogurt and milk and whisk to combine.
Add rolled oats, cinnamon, baking powder and salt, stirring until just combined.
Gently fold in the blueberries.
Divide batter into 12-cup muffin tin and bake for 30 minutes.