Cook the bacon in a skillet on medium heat until halfway done. Remove and place on paper towels. Let cool.

Preheat the oven to 350°F. In a large bowl, whisk the eggs. Add the onion, bell pepper, salt, and pepper. In a muffin pan, wrap the pieces of bacon along the bottom and sides to form cups. Pour in the egg mixture evenly, about ¾ full. Bake for 20 minutes or until the eggs are set.