Fair warning that this is a project and the recipe makes a lot. I didn’t see the sense in going to the trouble of making homemade gnocchi without making a big batch at once. The easy sage butter sauce just makes the perfect sauce to go with it.
Place the Sweet Potato (2) on a microwave safe plate and prick them all over with a fork so they don't explode. Then microwave them for 12 minutes to get them tender. Let them cool enough to handle, then cut both of them in half. Peel the skin away, it should fall away easily, and use a box grater to finely grate the flesh right into a mixing bowl.
Stir the grated sweet potatoes thoroughly with the Canned Pumpkin Purée (2 cup), Pumpkin Pie Spice (1 teaspoon), Paprika (1/2 teaspoon), Salt (2 pinch) and Freshly Ground Black Pepper (2 pinch).
On a clean counter surface, make a big well with the All-Purpose Flour (3 1/2 cup) and spoon the pumpkin sweet potato mixture into it. Crack the Egg (2) on top. Then use a fork to start beating the eggs while you start to incorporate the wet ingredients into the flour. Switch to using your clean hands to bring the dough into a smooth ball.
Knead the dough a couple of times to make sure it is well incorporated, but don't over handle it. Form it into a loaf and slice it into thin little slices. Make each slice into a thin, long log by rolling the slice under your hands back and forth. Then cut each slice into little 1-inch pieces.
Roll each piece over the back of a fork to make the signature ridges and lay them out on a lined sheet pan to hold them.
Get a large pot of water on to boil, and salt it generously. This is a lot of gnocchi. So I boiled them in 5 batches. Let them cook for a couple of minutes until they float to the top. As they float to the top, fish them out with a slotted spoon or fine mesh strainer and transfer them to a plate. Reserve some of the water.
Once all of the gnocchi are boiled, get out a large skillet and melt half of the stick of Butter (1/2 stick) in it over medium high heat. Add in half of the gnocchi and let them pan fry in the butter for 2-3 minutes to develop a light crust. Remove them from the pan to another plate and repeat it with the other half of gnocchi.
Then add the remaining Butter (1/2 stick) to the skillet along with the Fresh Sage (1 bunch) and Garlic (2 clove). Let the sage and garlic fry in the butter for another 3-4 minutes until the sage leaves are crisp. Transfer sage on a plate and discard the garlic. Whisk the All-Purpose Flour (2 tablespoon) in until the butter thickens into a paste. Then whisk in the Milk (2 tablespoon).
Finally, whisk some of the reserved starchy water from cooking the gnocchi in and the pinch of Salt (1 pinch) until you have a nice sauce. Toss the gnocchi into the sauce to coat it and take the pan off of the heat.
Crumble up the fried sage and sprinkle it into the pan with the pasta. Serve immediately in pretty bowls with a big sprinkle of Grated Parmesan Cheese (to taste) on top!