First, melt the butter and set aside to cool.
In a large bowl, mix together the flour, baking powder, soda, sugar, and salt.
In a measuring jug, whisk together the buttermilk, eggs, and vanilla extract.
Add the wet to the dry ingredients and lightly mix together. My trick is to stir it enough times to spell P.A.N.C.A.K.E, and then stop. The secret to thick, fluffy pancakes is not to over mix.
Fold in the cooled melted butter and blueberries and stir another few times. Lumps are perfectly fine, resist the urge to continue to mix.
Put a non-stick frying pan or griddle on medium/low heat. Allow to pre-heat for 5 minutes.
Spoon a big spoonful of the batter per pancake. Don't spread out the batter with a spoon, let it naturally spread out itself so it remains thick.
Cook for roughly 4 minutes on one side. Turn them over when you see bubbles forming on the top of the pancake and the edges aren't a shiny, wet batter.
Flip and cook for another on the other side for another 1-2 minutes.
Enjoy hot from the griddle with butter and maple syrup.