Pierce the potatoes with a fork and bake for 45-50 minutes, until soft. Let cool slightly.
When potatoes are cool enough to handle, cut in half and scoop the insides into a bowl. Add the butter, sour cream, and maple syrup. Mash or beat the potatoes with a whisk until smooth and fully incorporated. Season to taste with salt and pepper.
Transfer to a casserole and cover. Keep warm until ready to serve.