Preheat oven to 350°F.

Spray a 12-cavity muffin tin generously with nonstick cooking spray.

Place two sheets of paper towels on a large dinner plate, and set aside.

Set a large skillet over medium-high heat. Arrange the bacon strips in the skillet. Fry the bacon until brown and crisp, about 6-8 minutes, flipping once.

Transfer the bacon strips to the paper towel-lined dinner plate. Keep at least half of the bacon fat to cook the hash browns.

Return the skillet to the heat and add the thawed hash brown potatoes. Cook, stirring occasionally with a rubber spatula, until slightly golden brown, 4-5 minutes. Remove from the heat.

In a large mixing bowl, whisk together the eggs, sour cream, salt, and black pepper.

Using clean hands, crumble the bacon into small pieces and transfer to the egg mixture. Add the hash brown potatoes and shredded cheese. Fold with a rubber spatula until the bacon, potatoes, and cheese are evenly distributed.

Divide the mixture equally between the 12 cavities of the muffin pan.

Bake the casserole bites on middle rack of oven until golden brown on top and a toothpick inserted in the center comes out clean, 20-25 minutes.

Check to see that casserole bites are done. Remove from oven or add time as needed.

Allow the casserole bites to cool for 5 minutes in the pan. To remove, run a sharp knife around the edge of each casserole bite and lift up at an angle. Plate and serve.