Preheat oven to 400°F (200°C).
Scrub potatoes and pierce several times with a fork.
Rub potatoes with olive oil, sprinkle with salt, and place directly on oven rack or baking sheet.
Bake potatoes for 45 to 55 minutes until tender.
Cook bacon in a skillet until crisp; crumble when cool.
If using, cook and crumble breakfast sausage.
Slice green onions and sauté optional vegetables if desired.
Remove potatoes from oven and let cool slightly.
Slice each potato lengthwise and scoop out the centers, leaving a thin shell.
Mash scooped potato with butter, milk, salt, and pepper.
Stir in crumbled bacon, cooked sausage if used, most green onions, and shredded cheddar cheese.
Add beaten eggs and mix until well combined.
Refill potato shells with the loaded mixture and sprinkle extra cheese on top.
Bake again for 15 to 20 minutes until cheese melts and tops are golden.
Sprinkle remaining green onions on top and serve warm with hot sauce, salsa, or sour cream if desired.