Wash the potatoes to clean the skin.
Turn the oven to 400F.
Melt the butter on the stovetop over low - medium heat. Remove from heat when it's melted.
Using a small hole grater, grate the garlic cloves into the melted butter, along with any other seasonings (salt, pepper, anything else). You can pour it into the small pan directly, or pour the butter into a small bowl first.
Take each potato and using a sharp knife, cut thin slices that go almost to the bottom of the potato, but not quite. The base of each potato should still be held together, but the top of each potato will be cut as in the photos above.
Place potatoes on a baking tray, lined with parchment paper, oiled with a pastry brush or sprayed with nonstick cooking spray.
Using a pastry brush, brush the garlic butter mixture onto each potato, making sure to brush in between the crevices of each potato flap.
Leave a little bit of extra garlic butter to top the potatoes off when they come out of the oven.
Bake at 400F for 60-70 minutes. Poke the potatoes with a fork to check whether they are cooked or not after 60 minutes.
Once removed from the oven, brush with the remaining garlic butter right away and serve them warm!