Preheat oven to 425°F (218°C) and place 12 muffins liners in the pan.
In a bowl, combine the dry ingredients (flour, baking powder and salt)
In another mixing bowl, combine the wet ingredients (egg, sugar, vanilla, oil, sour cream and milk). Whisk together until combined.
Add dry ingredients to the wet ingredients. Mix by hand until the ingredients are combined.
Add a small amount of the plain batter to the muffin cups.
Lightly dust the blueberries with flour and then add them to the remaining batter. Gently fold the blueberries into the batter.
Spoon the blueberry mixture on top of the plain batter in the muffin cups. Make sure to fill them to the top.
Bake at 425°F (218°C) for 5 minutes.
Reduce heat to 350°F (177°C) and bake for 12-15 minutes.