Preheat your oven to 400°F and lightly grease a 9x13 inch baking dish (or similar size casserole dish). Peel and slice the potatoes into 1/4-inch rounds—uniform thickness is key so they cook evenly. In a bowl, toss the sliced potatoes with melted butter and 1/2 teaspoon salt until well coated. Layer the buttered potatoes across the bottom and slightly up the sides of your prepared dish, creating an even base. Bake this potato layer for 20-30 minutes until the potatoes are just beginning to soften but still hold their shape—they'll finish cooking when the casserole bakes again.

While the potatoes bake, heat a large skillet over medium-high heat and add the ground beef. Cook for 5-7 minutes, breaking it up with a spoon as it browns, until it's no longer pink. Drain off any excess fat using a colander or by tilting the pan and pressing the meat against the side with a spoon. Return the browned beef to the skillet and remove from heat. I like to drain the fat thoroughly here—it prevents the casserole from becoming greasy, which can happen easily with ground beef.

To the cooked ground beef from Step 2, add the cream of mushroom soup, 3/4 cup of the shredded cheddar cheese, milk, onion powder, garlic powder, and a pinch of salt and black pepper. Stir everything together until the cheese is evenly distributed and the mixture is smooth and well combined. The soup acts as a binding agent that creates a creamy filling when it bakes.

Remove the partially baked potatoes from the oven and spread the beef mixture from Step 3 evenly over the top. Use a spatula to create an even layer, making sure the filling reaches the edges. Return the casserole to the 400°F oven and bake for 15 minutes until the filling is heated through and slightly bubbly around the edges.

Remove the casserole from the oven and sprinkle the remaining 1 cup of shredded cheddar cheese evenly over the top. I always use freshly shredded cheese here rather than pre-shredded—it melts so much more smoothly and creates a better texture. Return to the oven and bake for 4-5 minutes until the cheese is completely melted and golden in spots.

Remove the casserole from the oven and let it rest for 2-3 minutes before serving. This brief rest helps the layers set slightly and makes for cleaner portions. Scoop into bowls or plates and serve hot.