Mix all dry ingredients in large bowl

Add milk and buttermilk. Stir until blended

Add sour cream. Stir until blended.

Melt butter over medium heat and set aside to cool.

Separate egg white and yolk. Blend yolks into batter 3 at a time and whites into separate bowl.

Meanwhile use hand mixer to whip egg whites until stiff and glossy. Set aside.

Stir melted and cooled butter into batter and mix.

Add in whipped egg whites.