1. Preheat oven to 350°
2. Wash, scrub and dry potatoes
3. Place on a baking sheet lined with Silpat or parchment paper
4. Bake until tender and skins start to wrinkle and pull away, about 1 hour
5. Allow the potatoes to cool enough to handle
6. Halve potatoes down the length and scoop out the center using a melon baller, spoon or small ice cream scoop. Place the centers in a medium-sized bowl and set aside (be sure to preserve the skins intact, leaving a little of the center)
7. Add crème fraiche and buttermilk to the bowl with the potato centers. Using a whisk, mash up and mix until smooth. Season with a pinch of salt and pepper
8. Lay potato skins on a Silpat or parchment paper-lined baking sheet, hollow-side-up, and scoop the filling evenly back into the skins
9. Top with crumbled blue cheese and place back into the oven for about 20 minutes or until the cheese looks bubbly and serve immediately

Note - For extra browning, finish under the broiler for 1 minute