Whisk flour, sugar, baking powder, baking soda, and salt in medium bowl to combine. Pour buttermilk and milk into 2-cup measuring cup. Mix yolk with melted butter, then beat into milk mixture until well blended. Whisk egg white in large bowl to stiff peaks. Make a well in center of dry ingredients in bowl; dump wet ingredients into dry ingredients all at once and whisk gently until just combined (a few lumps should remain). Do not over mix. Quickly, but gently, fold egg white into batter.

Meanwhile, heat a heavy-bottomed skillet or seasoned griddle over medium-high heat. (If using an electric griddle, heat to 375 degrees F.) Test skillet by sprinkling a few drops of water on it. When water forms beads and dances over skillet surface, it is hot enough. Lightly grease the skillet with bacon grease, vegetable oil, or spray with nonstick cooking spray.

Ladle 1/4 cup batter onto skillet for each pancake, making sure not to overcrowd. Scatter about 1 tablespoon blueberries evenly over each pancake. Cook pancakes until bottoms are golden brown and large bubbles begin to appear on top surface, 2 to 3 minutes. Using a spatula, flip pancakes and cook until remaining side has browned, 1 to 2 minutes longer (cooking the second side takes only about half as long as the first side and doesn't brown as evenly as the first side). Repeat with remaining batter, adding more oil to skillet as necessary. The pancakes are best served immediately but may be kept warm (* see note) in a low (200 degree F) oven until all the batter has been cooked.

Serve with butter and your favorite warmed syrup, or your favorite fruit compote, or dust with confectioners' sugar.

Serves 3 to 4 (makes about eight 3-inch pancakes).

* Note: To keep pancakes warm Place a large cooling rack (sprayed with vegetable cooking spray) on a sheet pan. Place the pan and the rack in a 200-degree oven. Place pancakes on the rack in a single layer, uncovered, for up to 20 minutes (any longerthey will start to dry out.) The warm oven keeps the pancakes hot enough to melt a pat of butter, and leaving the pancakes uncovered keeps them from becoming soggy.

Cooks Notes

When making the batter, take care not to overmix it, as too much stirring will develop the gluten in the flour and result in tough pancakes.

Have the milk and egg at room temperature so the melted butter doesn't harden.

A batter that's too thick can result in pancakes that are raw and wet in the middle. To avoid this, make the batter with just enough liquid so that it spreads into a pancake that is thin enough to cook through. Feel free to adjust the batter by adding more milk so that it flows off the ladle like very thick cream. Also, make sure the skillet is made of heavy-gauge metal that conducts heat well and evenly and that the skillet is heated up completely before cooking.

If the tops of the pancakes bubble and the bottoms don't brown, the heat source is too low, if they brown before they bubble, the heat is too high.

For more flavor if serving pancakes with bacon (or, if you have bacon grease), reserve the bacon drippings to grease the skillet instead of oil.

When fresh blueberries are not in season, frozen wild blueberries are a good substitute. To make sure that frozen berries do not bleed, rinse them under cool water in a mesh strainer until the water runs clear, then spread them on a paper towel-lined plate to dry.