3 c. all-purpose flour
3 Tbsp. sugar
1 Tbsp. baking powder
1 1/2 tsp. baking soda
3/4 tsp. salt
3 c. buttermilk
1/2 c. milk
3 eggs, separated
1/3 c. (5 1/3 Tbsp.) butter, melted
Combine flour, sugar, baking powder, baking soda, and salt. In another container, whisk together buttermilk, milk, and the egg yolks. With an electric mixer, beat the egg whites until stiff peaks form.
Whisking constantly, add melted butter to the milk mixture. Pour this mixture into the flour mixture and stir until just combined.
When the flour has been combined but the batter is still a little lumpy, heat a non-stick skillet or griddle to medium-low heat. While the skillet is heating, gently (but completely) fold beaten egg whites into the batter. When the skillet is hot, spray it with a little non-stick cooking spray and then just pour the batter into pancakes on the hot skillet.
Soon, you will start seeing bubbles. (For blueberry or chocolate chip pancakes, sprinkle those on top of the pancakes at this time.) When the bubbles pop and leave a hole, it's time to flip. Gently slide a spatula under the pancake and quickly flip it to the other side. The other side won't take quite as long as the first side--just check here and there and when the pancakes are golden brown on both sides remove from the skillet.
Top pancakes however you please, and serve.