Boil potatoes for about 12 - 15 minutes until they are tender. Drain the water using a colander, and then return the potatoes to the pan. Cover them to keep warm, and then set aside.
Heat a skillet over medium heat and cook the bacon until crisp, turning as needed.
Transfer the bacon to a plate lined with paper towel to drain. Let it cool, and then crumble it into pieces.
Mash the potatoes until light and fluffy. Add in cream cheese, butter, and sour cream. Continue mixing until well combined.
Whisk the egg in a bowl then add it to the mixer and mix about 1 minute.
Add in chives, shredded cheddar cheese, half of the bacon, salt and black pepper.
Stir together then transfer the mixture into a small baking dish sprayed with non-stick spray.
Top with cheddar cheese, crumbled bacon, and a sprinkle of chives.
Bake the casserole in the pre-heated oven until heated through. Serve and enjoy!