Preheat oven to 375°F (190°C).
 Wash potatoes and bake whole for 45–60 minutes until fork-tender.
 Slice each potato in half and scoop out most of the flesh into a bowl.
 Mash the potato with buttermilk until smooth and creamy.
 Season with salt and pepper if desired.
 Spoon the mixture back into the potato skins.
 Top with shredded cheese.
 Bake again for 15–20 minutes until golden and bubbly on top.