Melt 2 tablespoons of the butter in a large skillet over medium heat. Add the garlic and heat it for a couple of minutes (don't brown it). Add the pumpkin, 1/2 teaspoon salt and the chili powder. Cook this filling for a few minutes, stirring occasionally, to warm it and cook off some of the excess liquid. Remove from the heat and let it cool slightly while you get the other components ready.
Toast the pine nuts in a small skillet over medium-low heat, tossing and stirring occasionally, until golden. Remove them to a plate and set aside.
Next, make browned butter: In the same small skillet, melt the remaining 6 tablespoons butter over medium-high heat; let it cook and bubble up for an additional minute or so, until the foam is golden brown. Watch it carefully and take the pan off the heat as soon as it's ready. Finally, beat the egg with 1 tablespoon cold water. Now you're ready for Operation Ravioli.
Bring a pot of salted water to a boil. Lay out a few wonton wrappers at a time and spoon about 2 teaspoons of the pumpkin mixture in the middle of each one. Then, one at a time, dab your finger into the egg wash mixture and "paint" around the pumpkin on the wrapper. Lay a second wonton wrapper on top of each one, match up the edges and press the two wrappers together, gently pressing out any air bubbles as you go. To seal the ravioli, use a knife or square cutter to neatly trim the edges. Set them aside while you work on the rest.
Drop a few ravioli at a time into the boiling water. Boil them for 1 1/2 to 2 minutes, then remove with a slotted spoon and place on a platter or serving plates. Spoon a little bit of the browned butter over the ravioli, then sprinkle on the parmesan shavings, sage, toasted pine nuts and a little pepper.