Preheat the oven to 350 degrees F (175 degrees C). Grease a 12 cup muffin pan with cooking spray.
In a large skillet, fry the bacon pieces over medium heat until browned and crisp, about 8 minutes. Drain off half of the grease. Transfer the bacon and remaining grease to a large bowl. Stir in the shredded potato, shallot and Parmesan cheese. Divide this mixture evenly between the muffin cups. Pour eggs into each cup, filling to the top.
Bake in the preheated oven until the egg is firm, about 12 minutes. Remove from the oven and set the dial to Broil. Place a slice of tomato onto each cupcake and return to the oven. Broil for about 3 minutes, or until toasted. Allow to cool slightly, then arrange the cupcakes on a tray and top each one with a slice avocado, if using.
recipepes.comEggs n Bacon Cupcake, recipePT15MPT1H5455 calories