Preheat the oven at 400°F.
In a bowl mix flour, sugar, oats, salt and baking powder.
In a separate bowl whisk well egg, oil, vanilla, and milk. Fold the dry ingredients by mixing in the wet mixture one spoon at a time. The batter consistency should not be too runny and too thick. Comparatively this batter should be on thicker end. Mix in the blueberries. Do not stir too much otherwise the berries will get squashed. Fill the batter in muffin cups in a muffin tray using an ice-cream scoop.
Bake for 20 mins at 400°F in the oven till you get that nice rise and bake color on the top.
Tip: You can top the batter filled muffin cups with some powdered sugar and cinnamon powder before baking to give it a crisp flavorsome top.