Melt butter with the garlic in a skillet over medium heat and cook for a couple of minutes to release the garlic flavor. Add the pumpkin puree, salt and chili powder. Stir and cook over medium heat for a few minutes, stirring constantly. Remove from heat and let cool slightly.
Toast pine nuts in a small skillet over medium-low heat, tossing occasionally, until golden. Remove from heat and pour the pine nuts onto a small plate.
In a small skillet (you can use the same one you toasted the pine nuts in) brown the butter by melting it over medium-high heat, then letting it cook and bubble for an additional minute or so until the foam is golden brown. Remove from heat and set aside.
Assemble the ravioli: Lay out 18 wonton wrappers and put 1/2 teaspoon of the pumpkin mixture in the center. Beat the egg with 1 tablespoon water. Using your finger, smear the egg mixture all over the surface of one of the wrappers surrounding the pumpkin. Place a clean wrapper on top, matching up the edges. Press the edges together and use your fingers to press out any air pockets that form. Repeat with the rest of the wrappers. (Keep in mind the wrappers dry out quickly, so you might want to assemble 9 ravioli at a time, keeping the other wrappers covered.)
(If you like, you can trim the raviolis using a circular or square cutter to make the edges uniform. Totally optional!)
Bring a pot of water to a boil. 3 at a time, drop the ravioli into the water and cook for about 1 1/2 to 2 minutes. Remove with a slotted spatula and put the ravioli on a plate. Continue cooking the ravioli in batches of 3.
To serve, spoon a little browned butter onto each plate and smear it around. Place 3 ravioli on each plate, then spoon a little more browned butter over the top. Sprinkle on toasted pine nuts, sprinkle with a little black pepper, and sprinkle on shaved Parmesan. Finally, sprinkle on the sage and serve!