Preheat your oven to 375°F (190°C) and grease a 9x13 inch baking dish with non-stick spray or butter.

In a large skillet over medium-high heat, cook the ground beef until browned and no longer pink. Drain the excess fat. Stir in salt, pepper, garlic powder (and optional sage/thyme) to season the beef. Remove from heat.

In a large mixing bowl, beat the softened cream cheese until smooth. Gradually whisk in the eggs and milk until well combined and slightly frothy.

Stir the thawed hashbrowns, cooked ground beef, and 1 cup of the shredded cheddar cheese into the egg mixture.

Pour the mixture evenly into the prepared baking dish. Smooth the top with a spatula.

Bake for 40-45 minutes, or until the center is set and the edges are golden brown.

Remove from the oven, sprinkle the remaining 1 cup of cheddar cheese over the top, and bake for an additional 5 minutes until the cheese is melted and bubbly.

Let the casserole rest for 10 minutes before slicing and serving.