Preheat your oven to 325°F (165°C). Line a sheet pan with parchment paper for easy cleanup. Arrange the bacon slices in a single layer on the pan and bake for about 15 minutes, until crispy and golden.

In a large skillet over medium-high heat, add the sausage patties and cook them for 3–4 minutes on each side until they are golden brown and fully cooked through.

In a large mixing bowl, whisk together 12 large eggs, ¼ cup milk, salt, and pepper until smooth and well combined. Pour the egg mixture onto another parchment-lined baking sheet and spread it evenly.

Bake the egg mixture in the preheated oven for about 30 minutes, until the edges are slightly golden and the center is set. Remove from the oven, allow it to cool, and cut into 12 equal portions.

Split the English muffins in half and spread a thin layer of butter on each side. Set aside while assembling the sandwiches.

Assemble each sandwich by starting with the bottom half of an English muffin, placing a portion of baked eggs on top, followed by a piece of bacon or a sausage patty. Add optional ingredients if desired.

Wrap each assembled sandwich in parchment paper or plastic wrap and label with 'bacon' or 'sausage'. Place in a large freezer bag and seal tightly.

Store the sandwiches in the freezer for up to 3 months. Reheat them straight from the freezer, or thaw overnight for a quick meal.

Reheat the sandwiches in the microwave for 1–2 minutes, or in an oven for a crispier finish.