Twice Baked Potato Casserole

1hr 40min · 6 servings Ingredients • 3 to 4 large russet potatoes (2 ½ to 3 pounds total) • 8 slices cooked, drained and crumbled bacon, divided • 6 Tablespoons (3-ounces) unsalted butter, melted • ½ cup (4-ounces) sour cream • 1 ¼ cups (5-ounces) shredded extra sharp Cheddar cheese, divided • 1 teaspoon Kosher salt • ¼ teaspoon freshly ground black pepper • 2 Tablespoons chopped green onion tops for garnish (optional)