Meg D's Cheesy Potatoes

2 lb bag of frozen hashbrowns - the square ones.
1 can cream of chicken soup
12 oz sour cream
3 cups shredded cheddar cheese
2 T minced onion
3/4 cup butter (1/2 for potatoes and 1/4 for topping)
4 cups frosted flakes

Melt butter in micro. In large bowl place all ingredients except 1/4 cup butter and cereal. Once mixed place in 9 x 13 pan. Place cereal in zip lock bag, seal and smash. Add butter and mix together with hands. Pour cereal over the potatoes.
Bake covered for 1-1.5 hours. Removing cover for last 15 min.