In a large bowl, whisk together the dry ingredients until combined.
Add the sour cream, milk, eggs, and vanilla. Whisk together until combined. Do not overmix.
Fold ½ cup blueberries in just until incorporated.
Heat a large skillet over medium-low.
Add butter, and melt.
Spoon the pancake batter into the pan to make 3 or 4 pancakes.
Sprinkle blueberries over the top.
Cook for 2-3 minutes, until bubbles rise and pop. The edges should look drier and set.
Flip the pancakes, and then cook for another minute or until lightly browned.
Repeat with additional butter, blueberries, and batter.
Notes
All purpose flour: Be sure to properly measure the flour. Either weigh it or sift/stir it to break it up. Lightly spoon into the measuring cup and level.
Sour cream: Regular or lite sour cream will work. Plain Greek yogurt (whole milk, 2%, or nonfat) will also work.
Milk: Any milk from skim milk to whole milk will work. Whole milk will give you slightly richer, more tender pancakes.