Mix first 5 ingredients in large bowl to blend. Whisk buttermilk, egg yolks and 1 1/2 tablespoons melted butter in medium bowl to blend. Whisk into dry ingredients. Mix in cheese and ham. Beat egg whites in another bowl to stiff peaks. Fold whites into batter in 2 additions.
Heat 1 tablespoon melted butter in large nonstick skillet over medium heat. Working in batches, pour batter into skillet by 1/4 cupfuls. Cook until cakes are puffed and golden, adding more butter skillet for each batch if necessary, about 3 minutes per side. Transfer to plates. Serve with maple syrup.
