In a large mixing bowl, whisk together the all-purpose flour, sugar, baking powder, baking soda, and salt until well combined.

In a separate bowl, mix the buttermilk, large egg, melted butter, and vanilla extract until smooth and creamy.

Pour the wet mixture into the dry ingredients and gently stir together until no large floury patches remain.

If using frozen blueberries, toss them in a light coating of flour, then fold into the batter.

Heat a nonstick skillet over medium-low heat and lightly grease with cooking spray or butter.

Pour about ¼ cup of the batter onto the skillet for each pancake, immediately adding blueberries on top.

Cook for 2-3 minutes until bubbles form and edges look set, then flip and cook for another 1-2 minutes.

Transfer cooked pancakes to a plate and repeat with remaining batter.

Serve warm with maple syrup, butter, or more fresh blueberries.