Wash potatoes and add to a large pot. Fill with water. Bring to a boil. Boil for 20 minutes, until the potatoes are fully cooked.
Drain the water, rinse and drain again. Cut potatoes into small pieces. Add to a bowl.
In a small bowl mix together the mayonnaise, yogurt, hot sauce, garlic powder, apple cider vinegar, salt and pepper.
Pour dressing over the potatoes, while they are still warm. Stir and top with scallions. Add more salt if needed.