• Place the potatoes in a large pot and cover with cold water by 1 inch. Add 1 tablespoon of salt. Bring the water to a boil, reduce to a simmer, and cook uncovered for 10-15 minutes until the potatoes are tender and easily pierced with a fork.
• Drain the potatoes in a colander. Return the potatoes to the pot and add ¾ cup whole milk, 5 tablespoons butter, 1 cup sour cream, 1 teaspoon garlic powder, 1 teaspoon onion powder, 1 teaspoon salt, and ½ teaspoon black pepper. Mash the potatoes until they are smooth and the ingredients are well combined. Add more salt and pepper to taste if needed. Stir in 1.5 cups of cheese.
• Preheat your oven to 375°F. Coat a 2-quart casserole dish or a 9x13 baking dish with cooking spray or butter. Spread the mashed potatoes evenly in the dish. Top with the remaining ½ cup of cheese.
• Cover the dish loosely with foil. Bake for 20 minutes. Remove the foil, add the 6 oz bacon crumbles, and cook uncovered for 10-15 minutes until the cheese is golden and bubbly. Sprinkle with ¼ cup green onions or chives and serve.

Make Ahead Instructions

• Follow all the steps until step number 3 (don't preheat the oven). Cover the dish tightly with cling wrap and store in the fridge (can be refrigerated for up to 3 days). When ready to bake, take it out of the fridge and let it come to room temperature (about 2 hours) so it bakes evenly. Preheat the oven to 375°F and follow step number 4.