I used to make my own recipe for these back in my pregan days. I used copious amounts of sour cream, but pretty much they were like the video in the link below:
Twice Baked Potatoes - Food Wishes
Anyhow, I think I can veganize them as follows:
Bake several russet potatoes at 400ºF for an hour.
Placing them lengthwise, cut about 1/3 of the skin off, and scrape out the the potato from the skin. Save the cut part, and put it inside the hollowed out larger part.
Mix together the baked potato, some Earth Balance spread, some green onions, salt, pepper and cayenne pepper. When mixed well, add some Daiya cheddar shreds and some vegan sour cream. (The original recipe calls for butter, cheddar cheese and heavy cream) Mix all this together very well, until it is creamy. Fill the potato husks so they are heaping with potato filling.
Bake the filled potatoes at 400ºF for 20-30 minutes to brown them.
Eat and enjoy!