Adjust oven rack to middle position and spray a 13x9-inch casserole dish with nonstick cooking spray. Preheat the oven to 350°F.
Cook bacon over medium-low heat until crisp. Pour off all except 1-tablespoon bacon drippings, and reserve the drippings, in an airtight container, in the fridge for future use.
1 lb. bacon
Cook the diced onions in the tablespoon of bacon drippings still in the pan over medium-low heat until translucent and softened.
½ medium yellow onion
In a large bowl, whisk together ¼ cup melted butter, soup, sour cream, milk, cooked onions, 1 cup cheese and half of the crisped bacon pieces.
6 tbsp butter, 1 can cream of mushroom or cream of chicken soup, 12 oz. sour cream, ½ cup milk, 3 cups shredded cheese
Add the potatoes, and stir well.
1 30 oz. package frozen shredded hash browns
Transfer the potato mixture to the prepared pan and press it slightly down in an even layer. Top with 2 cups cheese.
Bake at 350°F for 45-60 minutes or until bubbly and hot throughout. If the cheese is browning too quickly, tent with aluminum foil. The internal temperature should register at least 165°F-175°F.
Remove from the oven and let set for 10 minutes before serving.
Serve with your favorite toppings, and enjoy!
cooked bacon, chopped tomatoes, crushed crackers, sliced scallions, sour cream, fried onions (French's)