These potato skin tacos are the marriage of two of my favorite things: tacos (obviously) and twice baked potatoes. If you've never had a twice baked potato, it basically involves baking a potato, scooping out the inside and mashing it with some butter and milk, stuffing it back into the potato and baking it a little more until the outside is crispy. But what if instead of stuffing the potato skin with mashed potatoes, you stuffed it with taco filling? And topped it with guacamole? What if?