Heat oven to 350℉ (175℃).
Line muffin tin with paper liners, or spray with cooking spray. Set aside.
Combine flour, sugar, baking powder, and salt in a large bowl.
Whisk to combine.
Add milk, eggs, vegetable oil, butter, and vanilla.
Whisk until combined, but not smooth.
Fold in blueberries.
Use a 3 Tablespoon scoop to portion batter into prepared pan.
Bake for 25 minutes, or until golden brown.