Preheat the oven to 180°C. Line a 12-hole standard muffin tin with paper cases.
Sift the flour, sugar and cinnamon into a large mixing bowl. Tip the husks from the sieve into the bowl. Stir in the oats and make a well in the centre.
Use a fork to whisk the milk, oil, eggs and vanilla in a bowl. Add to the dry ingredients along with the mashed bananas, and fold together until just combined. Gently fold in the pecans and blueberries.
Divide the batter among the muffin cases. Bake the muffins for 20 minutes, until risen, golden and springy to a gentle touch. Serve warm or at room temperature.
Each serving provides 930 kJ, 222 kcal, 6 g protein, 10 g fat (1 g saturated fat), 28 g carbohydrate (10 g sugars), 4 g fibre and 154 mg sodium.