In a medium bowl, mix pumpkin, squash, cream cheese, nutmeg, parmesan, egg and 2 pinches each salt and pepper.
Line a baking sheet with parchment paper and set aside. Spoon a tablespoon of the pumpkin-cream cheese filling into the center of 16 pasta squares, brush the edges with water, top with the remaining 16 squares and press to seal, gently squeezing out air. Arrange in a single layer on the baking sheet.
Bring a pot of salted water to a boil. Meanwhile, in a large skillet, melt butter; keep warm.
Working in 3 batches, cook the ravioli in the boiling water until they float to the surface, about 3 minutes. Using a slotted spoon, add the ravioli to the butter in the skillet and turn gently to coat.
Divide the ravioli; season with salt and pepper. Scatter toasted pumpkin seeds and shaved parmesan on top.