In a large bowl, stir together oatmeal, flour, sugar, baking powder, baking soda, salt and nutmeg. In another large bowl, mash banana with a masher or fork. Whisk in eggs and yogourt. Stir in milk and vanilla. Make a hole or a well in mixture, pour in banana mixture and stir until blended. Stir in melted butter.

Coat a large frying pan with butter and set over medium heat until hot. When butter is foamy drop the batter by ¼ cupfuls, spacing the pancakes about 2 inches apart. You should be able to fit about 3 or 4 in the pan. Be careful not to crowd pan. Cook until holes form on the top, and the edges are golden, about 2 to 3 minutes. Turn and cook until golden brown on each side, about 3 to 4 min more. Remove to a platter. Cover to keep warm or hold warm in an oven heated to 275F. Top with maple syrup and icing sugar if desired.