Preheat the oven to 350 degrees. Place the potatoes on a baking sheet and bake until fork tender, about 1 hour. Remove from the oven and let cool for about 5 minutes, or until cool enough to handle with care. Peel and discard the skin. I cut mine in half and the skin basically falls right off of them with barely any effort. Place the potatoes in the bowl of a food processor*.
The original directions are for a food processor, however I have also made this using a hand potato masher and the blender, pureeing the potatoes in two separate batches. It worked great, but it is definitely simpler with the food processor.
During the holidays, I often make these the day before. I cool them completely and then cover the potatoes and place them in the refrigerator. A couple hours before serving them, set them on the counter to come closer to room temperature. Then, warm them in the oven at 350 degrees for about half an hour. Stir before serving.
ALTERNATIVE to the pricey vanilla bean - I've successfully used vanilla bean paste for this recipe and I've also used vanilla extract. Vanilla beans are my first choice, followed by vanilla bean paste, lastly, I have used vanilla extract in a pinch.