Preheat Oven: Preheat the oven to 475°F (245°C). Generously butter a 6-cup jumbo muffin pan.

Prepare Hash Brown Cups: In a large bowl, mix the thawed hash browns with melted butter, egg whites, salt, and pepper.

Divide the hash brown mixture among the muffin cups, pressing firmly into the bottom and up the sides to form cups.

Bake in the preheated oven for 15 minutes or until the edges are golden brown and the hash browns have set.

Sauté Vegetables and Ham: While the hash browns are baking, heat a little olive oil in a skillet over medium heat. Sauté onions, bell pepper, and ham until soft.

Add spinach and cook until wilted. Season with salt and pepper to taste.

Assemble Breakfast Cups: Once hash browns are baked, reduce the oven temperature to 350°F (175°C).

Spoon the ham and vegetable mixture into each hash brown cup. Top each with a generous amount of cheese.

Bake with Eggs: Return to the oven for about 3 minutes or until the cheese melts.

Crack an egg into each cup, season with a bit more salt and pepper, and bake for 8-12 minutes, depending on how set you prefer your eggs.

Serve: Allow to cool slightly before removing from the pan and serving.