Scrub and wash the potatoes thoroughly. Pat the potatoes dry with paper towels. Pierce the potato in several different places with a sturdy fork.
Place the potatoes directly on the rack of an oven preheated to 400 degrees. Bake for an hour, or until the potatoes are soft and fork tender.
Let the potatoes cool, just until cooled enough to handle. Cut them in half lengthwise. Using a spoon, scoop out most of the potato inside into a waiting mixing bowl, leaving a 1/4" rim left, to create a sturdy potato shell/bowl.
Using a potato masher, or a hand mixer, mix or whip the potato pulp until smooth. Stir in the cheese, half and half, pumpkin, sage, salt & pepper until the mixture's smooth.
Transfer the potato shells to a baking sheet. Scoop, or pipe, the filling back into the potato shells, dividing it evenly as you go. Bake the potatoes an additional 10 minutes, again at 400 degrees, or until the filling's heated through.
Serve immediately, and enjoy!