Preheat oven to 400°F. Scrub potatoes, cut off ends, and prick all over with a fork. Brush all over with oil. Place on a baking sheet and bake for 40 minutes. Remove and cool until easy to handle. Cut each potato in half lengthwise. Scoop potato flesh into a small mixing bowl, leaving 1/4-inch shell of potato in skins. Return shells to the baking sheet.
Mash the sweet potato pulp in the bowl with a fork and mix in 1/4 cup yogurt, the adobo sauce, white parts of the green onions, and salt.
Spoon the mashed mixture into the sweet potato shells. Bake, covered loosely with foil, 5 to 10 minutes or until heated through. Top each with remaining yogurt and green onions.