Sift first 6 ingredients into large bowl. Whisk buttermilk, eggs and melted butter in medium bowl to blend. Add buttermilk mixture to dry ingredients and whisk until blended and smooth. Gently fold in blueberries.
Preheat oven to 200°F. Lightly coat bottom of griddle pan with butter. Heat over medium heat. Working in batches, pour ¼ cup batter into skillet for each pancake. Cook until bottoms are golden, about 1 ½ minutes. Turn pancakes and cook until second sides are golden, about 1 minute. Transfer to baking sheet; place in oven to keep warm. Repeat with remaining batter, adding more butter to skillet as necessary.