Heat oven to 350 degrees and grease a 9×11- inch pyrex dish or similar size casserole dish.
Cook bacon in a nonstick skillet. Remove to paper towel lined plate. Crumble once cooled.
Remove all but 2 tablespoons of bacon grease from skillet. Heat skillet over medium heat and add onion and hash browns. Cook until hash browns are lightly browned, flipping several times.
Place half of hash browns on bottom of baking dish. Add 1/2 bacon and 1/2 cheese. Repeat layers.
Combine eggs, evaporated milk, whipping cream, salt, and pepper in a medium bowl. Mix well.
Pour egg mixture over top of hash browns.
In a small bowl, toss panko crumbs with melted butter. Sprinkle on top of casserole.
Bake uncovered for 30-35 minutes.