In a large bowl, whisk together the butter, eggs, milk, vanilla, and sourdough starter until combined.
Whisk in the remaining ingredients one at a time (the flour, baking soda, baking powder, and salt).
Gently fold in the blueberries.
Preheat the griddle.
Once the griddle is hot, gently stir the pancake batter and use a 1/3 measuring cup to pour the batter onto the grill. (If the batter is too thick, add 1 teaspoon of milk at a time until you reach your desired consistency.)
Cook the pancakes for 2-3 minutes, and then flip them over, cooking them for 1-2 more minutes.