Bacon-Cheddar Waffles

Preheat oven 200 degrees F. Cook bacon in large skillet over medium-high heat until crisp and brown, 8 minutes. Transfer to a paper towel-lined plate to let drain, then chop. Pour off all but 1 tablespoon bacon grease from pan. In a small bowl, whisk together flour, baking soda, baking powder, salt, and pepper. In a medium bowl, whisk together 1 egg, buttermilk, and 1 tablespoon melted butter. Add dry ingredients to wet ingredients, whisking until smooth. Add bacon, cheddar, and almost all scallions to batter. Heat a waffle maker and brush with melted butter. Cook waffles in batches until golden. Heat skillet (with 1 tablespoon bacon grease) over medium-high heat and cook remaining eggs until whites are set and yolks are still soft. Season with salt and pepper. Serve waffles with an egg on top and garnish with remaining scallions.