Peel and slice the potatoes into 1" pieces. Boil until fork tender. Test the potatoes for doneness by inserting a fork into one of the potato pieces. If the potatoes are soft, they are done, if they are still hard in the middle, cook longer. Drain and mash. Add the cream cheese and butter, beating until blended. Add the remaining ingredients and beat until the potatoes are creamy without lumps. Place potatoes in a greased casserole dish and top with shredded cheddar cheese. Bake in a 400 degree oven for 20-25 minutes until bubbly and cheese is golden brown.
1 five pound bag of potatoes6 oz cream cheese, softened3 cups sour cream3 tablespoons butter1 teaspoon garlic powder2 cups cheddar cheese, shreddedsalt and pepper to taste