Make Best Cheesy Potato Casserole Recipe: creamy shredded potatoes, sharp cheddar, and a buttery cracker crust in one pan.
Preheat the oven to 350°F (175°C) so it's ready when the casserole is assembled; this small step sets the stage and you can gather the bowls and measuring spoons while it warms. Think of it as giving the oven a gentle head start while you focus on building the creamy, cheesy filling.
In a large mixing bowl combine the frozen shredded hash browns (still slightly icy but loosened), shredded sharp cheddar, sour cream, and the condensed cream of chicken soup. Add the chopped onion, salt, and black pepper. Use a sturdy spoon or spatula to fold everything until the mixture becomes uniformly creamy and studded with orange cheddar flecks and tiny onion bits—moist but not soupy, the shredded potato strands coated in a cohesive cheesy sauce.
Spoon the mixed potato-and-cheese mixture into a 9x13-inch rectangular glass baking dish and spread it evenly, pressing gently so the surface is flat and the mixture reaches the edges. Smooth the top with the back of a spoon or an offset spatula until you see a compact, slightly textured surface where the cheddar peeks through in places.
In a small bowl combine the crushed butter-flavored crackers with the melted butter, stirring until the crumbs are uniformly glossy and just clumping together. The topping should be wet enough to brown crisply in the oven but still granular—small buttery crumbs that will form a crunchy, golden crust.
Evenly sprinkle the buttery cracker crumbs across the smoothed potato surface so the topping creates a continuous, thin blanket of golden crumbs; gently press a few crumbs into the edges for even browning. The assembled, unbaked casserole should look compact, cream-colored with orange cheese highlights, and evenly coated with an unbaked cracker crust.

Bake in the preheated oven for about 45 minutes, or until the center is bubbly and the topping turns an even golden-brown with slightly darker caramelized edges. The casserole transforms in the oven: the cheese melts into a glossy, cohesive layer and the cracker topping crisps into a thin, shattering crust while the interior becomes tender and steaming.
Remove the casserole from the oven and let it rest for a few minutes so the melted interior settles and slices hold together; sprinkle with a few fresh parsley flecks if desired for color contrast. Serve directly from the same rectangular glass baking dish, the top crackling with golden crumbs and the interior creamy and pillowy.
