In large bowl of electric mixer, at high speed, beat eggs until fluffy - about 2 minutes.

Into eggs, sift flour with baking powder, salt, and granulated sugar. Add brown sugar; beat until smooth.

Stir in buttermilk and butter just until combined; do not overbeat.

Meanwhile, slowly heat griddle or heavy skillet. To test temp, drop a little cold water onto hot griddle; water should roll off in drops.

Use 1/4 C batter for each flapjack; cook until bubbles form on surface and edges become dry. Turn, cook 2 minutes longer, or until nicely browned on underside.