Preheat the oven to 350°F (175°C).

Grease a 12-cup muffin pan generously. A silicone muffin pan works best for easy removal.

Heat a skillet over medium-high heat and brown the beef sausage until fully cooked. Drain excess fat and transfer to a paper towel-lined plate.

Add a small amount of cooking fat to the skillet. Cook the frozen hash browns until lightly browned and slightly crispy.

Divide the hash browns evenly among the muffin cups.

Add additional cooking fat if needed and sauté the diced peppers and onion until tender.

Spoon the cooked sausage over the hash browns, followed by the sautéed vegetables.

In a large bowl, whisk together the eggs, salt, and pepper until well combined.

Pour the egg mixture evenly into each muffin cup. The cups will be nearly full.

Bake the Sausage Hash Brown Egg Muffins for 18–22 minutes, or until the centers are set and cooked through.

Remove from the oven and allow the muffins to rest for 5–10 minutes before serving.

Carefully remove from the muffin pan and enjoy warm.