Preheat oven to 425°F. Prepare mini doughnut pan with vegetable pan spray.
In large bowl, stir together flour, sugar, baking powder, salt and nutmeg. Add buttermilk, egg and butter; stir until just combined. Fill each doughnut cup approximately 1/2 full with 1 tablespoon of batter. Spread batter around center post to edges of cup.
Bake 6-7 minutes or until the top of the doughnuts spring back when touched. Cool
in pan 3 minutes; remove to cooling grid. Doughnuts are best served fresh.