Cook the bacon on a baking sheet with foil for about 15-20 minutes at 375F.
While the bacon is cooking, heat 1/3 cup of mozzarella at a time on clean pan on medium heat for the shells.
Wait until the cheese is browned on the edges (about 2-3 minutes).
Use a pair of tongs to lift the shell up and drape it over a wooden spoon resting on a pot. Do the same with the rest of your cheese, working in batches of 1/3 cups.
Cook your eggs in the butter, stirring occasionally until they’re done. Season with salt and pepper.
Spoon a third of your scrambled eggs, avocado, and bacon into each hardened taco shell.
Sprinkle cheddar cheese over the tops of the breakfast tacos. Add hot sauce and cilantro if you’d like!