In a large bowl, whisk together the dry ingredients: flour, baking powder, baking soda and salt.
In a measuring cup or medium bowl, whisk together the wet ingredients: buttermilk, egg, maple syrup and vanilla extract.
Create a well in the middle of the dry ingredients and pour the wet ingredients into the well. Whisk together until just combined; the mixture will be pretty thick and there will be some lumps, but there should be no dry flour remaining.
Melt the butter in a large skillet over medium heat. Once the butter is hot and lightly bubbling, scoop a few pancakes onto the pan, using about 1/3 cup of batter for each. Spread out the batter into round-ish pancake shapes and scatter a few blueberries over the top of each.
Cook the pancakes for 3-4 minutes, until the bottom is golden-brown and small bubbles are forming on the top. Flip and cook for an additional 2-3 minutes.
Serve warm with plenty of maple syrup and more butter, if desired.
Notes
If you don’t have buttermilk, you can make your own by combining 1 cup + 2 tablespoons of milk (ideally 2% or whole milk) with 2 tablespoons of lemon juice or white vinegar. Whisk them together, then set the mixture aside to curdle for a few minutes before using in place of the buttermilk.