Preheat oven to 350 degrees F.
Remove the top 1/2-inch of each pepper. Discard the tops and seeds. Arrange the peppers, cut side up, in an 8 by 8-inch glass baking dish. Fill the bottom of each pepper evenly with hash browns and bacon.
In a large bowl, combine the eggs, cheese, milk, baking mix, sour cream, green onion, salt, and pepper. Whisk until combined. Evenly distribute the egg mixture into each pepper. Bake until a wooden pick inserted in center comes out dry, about 45 minutes. Remove from the oven, garnish with cheese and serve immediately.