Preheat oven to 450 degrees. Lightly grease 6 cups of a standard-size muffin pan with vegetable oil. In a large bowl,
combine cornmeal, flour, sugar, baking powder, and salt. Make a well in the center; stir in buttermilk, oil, egg, and scallions. Fill muffin cups two-thirds full and bake until a toothpick inserted in center of a muffin comes out clean, 10 to 13 minutes.