Heat the oven to 350°F. While the oven is heating, cook the bacon and onion in a 10-inch skillet over medium heat until the bacon is crisp, stirring occasionally. Spoon off any fat.
Stir the bacon mixture, soup, sour cream, 4 tablespoons butter, potatoes, broccoli, green onion and cheese in a large bowl. Season the mixture, if desired. Stir the panko and remaining butter in a small bowl. Spoon the potato mixture into a lightly greased 9x9x2-inch baking dish. Sprinkle with the panko mixture.
Bake for 45 minutes or until the mixture is hot and the panko mixture is golden brown.