Preheat the oven to 350° F. Spray a 9-inch square casserole dish with nonstick
Place the pancake mix, 1/2 cup of milk, butter, 1 egg, and 1/4 teaspoon of salt
in a large mixing bowl. Whisk until smooth and combined. Pour into the baking dish and smooth into an even layer. Sprinkle with 3/4 cup of shredded cheese.
In a separate bowl, whisk the remaining 4 eggs, 1/4 cup of milk, 1/2 of teaspoon
salt, and black pepper until smooth. Fold in the chopped bell pepper, green
onions, and bacon. Pour into the baking dish. Sprinkle with the remaining 1/4 cup of shredded cheese.
Transfer the dish to the middle rack of the oven. Bake for 25 to 30 minutes, until the top is set and lightly golden brown.
Remove the dish from the oven. Allow to cool for 15 minutes before slicing and serving. Serve garnished with avocado slices, if desired.
1/2 cup diced ham may be used instead of bacon. For a vegetarian casserole, simply omit the meat or use a plant-based meat substitute.
For 12 servings, double all ingredients and bake in a 9-by-13-inch (3-quart) casserole dish for 35 to 40 minutes.