Preheat oven to 425 degrees F. Bake sweet potatoes for about 1 hour or until cooked through. Alternately, microwave for 5-8 minutes. Allow potatoes to cool.
Once potatoes are cool enough to handle, cut in half and remove flesh, leaving ¼-½ inch intact.
Place potato skins on a sheet pan. Mix together melted butter and Java Rub. Brush the insides of the potato skins with the mixture. Bake for 15 minutes or until skins are starting to crisp.
Remove potato skins from oven. Fill each with black beans and cheddar cheese. Return to oven and bake for about 10 minutes more until cheese is melted and starting to brown.
Meanwhile, mashed avocados. Season with salt to taste.
Serve potatoes skins with mashed avocado, sour cream, and scallions.
