This 4-ingredient oven baked potato casserole using frozen shredded potatoes is my kind of holiday side: you literally dump a bag of completely frozen hash browns into a pan, scatter a few everyday staples over the top, and let the oven do all the work. It’s inspired by those classic Midwestern potato bakes you see at church potlucks, but pared way down so it fits into a weeknight or a busy holiday morning. The result is a golden, cheesy, buttery pan of comfort that feels like it took all afternoon—while you were actually doing a million other things.
Serve this casserole hot, straight from the oven, with roasted turkey, ham, or meatloaf for the holidays, or alongside simple baked chicken or pork chops on a regular weeknight. A crisp green salad or steamed green beans help balance the richness, and a side of cranberry sauce or applesauce adds a nice sweet-tart contrast. If you’re serving brunch, pair it with scrambled eggs, sausage, and fresh fruit for an easy, crowd-pleasing spread.
4-Ingredient Oven Baked Potato Casserole
Servings: 6-8

Ingredients
1 (28–32 oz) bag frozen shredded hash brown potatoes, completely frozen
8 tbsp (1 stick) unsalted butter, cold, cut into small squares
2 cups shredded cheddar cheese, divided
1 1/2 cups whole milk
1 tsp kosher salt (optional, to taste)
1/2 tsp black pepper (optional, to taste)
Directions
Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch metal baking dish with butter or nonstick spray.
Open the bag of frozen shredded hash brown potatoes and dump the potatoes straight into the prepared baking dish. Spread them into an even layer, but do not thaw them first—you want them completely frozen.
Sprinkle 1 1/2 cups of the shredded cheddar cheese evenly over the top of the frozen potatoes, letting some fall down into the shreds.
Scatter the cold butter squares all over the top of the cheese and potatoes. It will look like little yellow squares dotted across the surface—that’s exactly what you want. As it bakes, the butter will melt down into the potatoes and help them turn rich and golden.
Pour the milk evenly over everything in the baking dish, trying to cover as much surface area as possible so it can soak down into the potatoes while they cook.
Season the top lightly with salt and black pepper, if using. (If your cheese is very salty, you can skip the extra salt.)
Cover the baking dish tightly with aluminum foil and place it on the center rack of the preheated oven. Bake for 45 minutes, until the potatoes are tender and most of the liquid has absorbed.
Carefully remove the foil and sprinkle the remaining 1/2 cup shredded cheddar cheese over the top of the casserole.
Return the uncovered dish to the oven and bake for another 15–20 minutes, or until the top is bubbly, the edges are lightly browned, and the cheese has melted into a golden layer.
Let the casserole rest for 5–10 minutes before serving so it can set up slightly. Scoop into squares or big spoonfuls and serve warm.
Variations & Tips
For extra flavor without adding more ingredients, use a sharp cheddar or a blend of cheddar and Monterey Jack. If you want a creamier, richer version, swap 1/2 cup of the milk for heavy cream. You can also stir in 1/2 teaspoon of garlic powder or onion powder with the salt and pepper for a little something extra. To make it a brunch main, scatter cooked, crumbled bacon or breakfast sausage over the potatoes before adding the cheese and butter. If you prefer a smaller batch, halve the recipe and bake it in an 8x8-inch pan, checking for doneness about 10 minutes earlier. Leftovers reheat well in the oven or air fryer—just cover with foil so they don’t dry out, then uncover at the end to re-crisp the edges.