Preheat the oven to medium-high heat or 350 degrees F. Then, align 15 muffin cups with paper liners.
Meanwhile, in a small bowl, start mixing the flour, baking powder, and salt together, then set aside.
On the other hand, blend the butter and sugar together in a large bowl. Transfer the batter to a blender and beat on a medium speed until it appears thick.
While beating, incorporate the eggs. Continue to beat until they appear well-combined.
Incorporate the rest of the dry ingredients and blend again on low speed. Mix thoroughly until it appears thick.
Turn off the mixer for a while then add vanilla extract and milk. Mix them again together until the batter becomes soft yet thick.
Using a spatula, add the blueberries. If you used frozen blueberries, expect the batter to become very thick. Don't worry this is normal.
Pour the batter evenly into the muffin pans. Fill each space for about 2/3 full.
If you desired, sprinkle a teaspoon of sugar on top of the muffin.
Bake the muffins for 25 minutes.
Let the muffins cool for 5 minutes.