This Hashbrown Casserole is creamy, cheesy, loaded with tender potatoes, and topped with crunchy cornflakes! Only 10 minutes of prep for the BEST side dish for dinner or breakfast.
This hashbrown casserole is what dreams are made of — fluffy, tender potatoes smothered in a creamy, cheesy sauce, and topped with crispy cornflakes . . . like I said, this is what dreams are made of.
I LOVE this as a side for dinner, but it’s also great served for breakfast as a side for bacon, eggs, and toast!
Ingredients
This hashbrown breakfast casserole is made up of the simplest, yummiest ingredients!
- Unsalted Butter – used to cook the onion. Adds a rich flavor to the whole dish.
- Onion – adds texture and caramel-y, sweet flavor.
- Salt and Pepper – enhances flavors and adds just a bit of spice.
- Sour Cream and Cream of Mushroom – make a super creamy and tangy base for the casserole.
- Colby Jack Cheese – I love the smooth but slightly tangy flavor of this cheese but other kinds will work as well!
- Hashbrowns – use frozen, shredded hashbrowns for easy prep!
- Cornflakes – a delicious, crispy topping for the casserole.
How to make
Only 10 minutes of prep for this super yummy recipe!
- Melt butter in a non-stick sauté pan then add onions, salt, and pepper and cook until onions are softened.
- Pour onions into a large mixing bowl, add in sour cream, cream of mushroom, and shredded cheese then stir to combine.
- Mix in frozen hashbrowns.
- Pour the mixture into a greased baking dish and bake for 1 hour.
- Sprinkle with crushed cornflakes, top with cooking spray, then bake for another 10 minutes. Serve and enjoy!
Do you thaw frozen hashbrowns before making casserole?
Nope! That’s one of the great things about this hashbrown casserole recipe. You don’t have to do anything extra with the hashbrowns, just mix the frozen hashbrowns right in!
Can you use fresh potatoes?
I don’t recommend this. Since frozen hash browns are pretty dry, the extra moisture in fresh potatoes will water down the casserole.
If you do choose to use fresh potatoes, you’ll need to wash, peel, and shred them with a box grater, then you’ll want to squeeze out the excess water really well before incorporating them into this recipe.
What cheese to use
I chose to go with colby jack cheese because I think its mild flavor goes perfectly with the sour cream and cream of mushroom.
However, if colby jack isn’t your thing, feel free to use a different kind. Cheddar is another classic, but pepperjack would be great if you’re looking for a little spice!
Hashbrown casserole toppings
The classic hashbrown casserole topping is cornflakes—which is what we’re using today! I love the crunchy crispiness they give to the casserole.
You can also use crushed crackers, crispy bacon bits, Panko breadcrumbs, or a combination of any of the above. Whatever you choose to do is sure to be delicious!
Tips
- Use frozen hashbrowns. Fresh potatoes contain too much moisture so the casserole will be too watery if you don’t prep them properly. Frozen hashbrowns are already ready to go!
- Mince onion finely. You want pretty small chunks of onion so the flavor doesn’t overpower each bite. You’ll also want to sauté them in the butter before incorporating them into the recipe to take out that raw “bite”.
- Don’t skip the cornflakes. The crispy texture offsets the creaminess of the rest of the casserole perfectly.
Variations
- Add meat. Try ground sausage, cubed ham, diced chicken, etc.
- Mix in more veggies. Bell peppers, mushrooms, broccoli, or spinach would all be delicious. Whatever you use, sauté them with the onion until they’re crisp-tender. You might also need to drain any excess liquid they may produce.
- Use a different topping. Crumbled, buttery crackers or Panko breadcrumbs are also delicious toppings.
- Give it a Mexican or Southwestern flavor twist. Try using Mexican cheese instead of colby jack, adding a touch of taco seasoning, maybe some chipotles in adobo, and stirring in some green chiles. Serve with a dollop of salsa and sour cream!
What to serve with hashbrown casserole
Hashbrown casserole is delicious on its own but I also love serving it with a couple more of my favorite breakfast dishes:
- Biscuits and Gravy
- Frittata
- Cinnamon Rolls
- Berry Fruit Salad
- Scrambled Eggs, Bacon, Avocado Toast, etc.
If I’m serving it for dinner, I love it paired with:
Can hash brown casserole be made in advance?
It sure can! To make your casserole ahead of time, prep the recipe as directed, cover the baking dish with foil, then store in the fridge up to 24 hours. When you’re ready to serve, bake as directed and enjoy!
You can also wrap it in freezer wrap and keep it, unbaked, in the freezer for up to 2 months. Make sure you thaw it fully in the fridge before baking as directed.
Keep in mind, storing it in the fridge or freezer may increase the baking time a bit so be sure the casserole is warmed through before serving!
How to store
Already baked hashbrown casserole can be stored in an airtight container in the fridge for 3 days or in the freezer for up to 2 months.
To reheat, thaw in the fridge if frozen then cover with foil and bake at 325ºF for 15-20 minutes. You can also heat single servings in the microwave but the cornflakes won’t be as crispy.
– Jennifer

Hashbrown Casserole
Equipment for this recipe
Ingredients
- ½ cup unsalted butter 1/2 cup = 1 stick
- 1 yellow onion diced
- 1 teaspoon salt
- ½ teaspoon pepper
- 1 (16 oz) container sour cream
- 1 (10.75 oz) can cream of mushroom
- 1 (8 oz) block colby jack cheese shredded
- 1 (30 oz) bag frozen shredded hashbrowns keep frozen
- 2 cups lightly crushed cornflakes
Recipe Video
Instructions
- Preheat oven to 350 degrees F and grease a 9x13 inch baking dish with cooking spray. Set aside.
- Melt butter in a non-stick sauté pan over medium heat.
- Add in onions, salt, and pepper and cook, stirring regularly, for 5 minutes or until slightly softened.
- Pour onion mixture into a large bowl and add in sour cream, cream of mushroom, and shredded cheese.
- Stir to combine.
- Add in frozen shredded hashbrowns and mix, breaking up any large chunks as you go, until well combined.
- Pour into prepared baking dish.
- Bake in preheated oven for 1 hour.
- Sprinkle with crushed cornflakes, then gently press down on the cornflakes so they stick to the potatoes - be careful to not touch the hot pan.
- Spray the top generously with cooking spray.
- Bake for an additional 10 minutes.
- Cool slightly, serve, and enjoy!
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Nutrition Information
*Note: Nutrition information is estimated and varies based on products used.
Anonymous Cedar Rapids, Iowa
Anonymous Cedar Rapids, Iowa
Shelby Orlando, Florida
Richard United States
Rahul Birmingham, Alabama
Jennifer @ Show Me the Yummy