Preheat oven to 375°F.
Peel squash, cut in half and scoop out seeds. Cut into a 1/2-inch dice. Transfer pumpkin to a medium bowl and add the olive oil , sliced onions and the spices. Toss well and spread onto a baking sheet. Roast pumpkin and onion mixture for 30 minutes until onions are caramelized and the pumpkin is almost tender. Let cool to room temperature. Pumpkin may be prepared up to two days ahead.
On a floured work surface, roll the pie pastry into a 12" round. Transfer to an ungreased baking sheet or pizza pan. Spread pumpkin mixture over the dough, leaving a 1 1/2-inch border. Scatter the goat cheese over the top and sprinkle with the Parmesan cheese. Fold the border over the vegetables, pleating the edges. Leave the center open.
Bake gallette until golden brown, 30 to 40 minutes. Remove from the oven, let stand for 10 minutes before cutting into 8 wedges.
