If using frozen blueberries, take it out of the freezer now and allow it to defrost as you move onto making the batter.
Combine all pancake batter ingredients in a large mixing bowl and whisk until a smooth batter is formed (no lumps!). (see note 3)
In a non-stick pan on medium heat, swirl half the butter and allow it to coat the entire pan.
Spoon pancake batter into the pan, size of pancakes are up to you, I spoon enough batter per pancake so that 4 fits in a pan comfortably. Reduce heat slightly down to medium/low.
Scatter blueberries onto pancake batter in the pan and cover with a little more batter.
Once the batter starts to bubble a little and pan side is lovely golden, flip the pancakes. Pancakes are ready when both sides are golden.
Repeat until you've turned all of the batters into blueberry pancakes!