One of the culinary debates I seem to have repeatedly is over the proper way to roast winter squashes, including pumpkins. To roast a winter squash, typically you split them in half, seed them, and pop them in a medium hot oven for an hour. There is little contention over these steps. However a war rages over whether to roast them cut-side up or down.
Normally, I like to see both sides of these sorts of debates, but in this case there is a correct answer. Roast your squashes cut side up. With the cut side down, the moisture doesn’t have any place to go so you are essentially steaming the vegetable. With the moisture staying in the squash, the flavor doesn’t have an opportunity to intensify. Also, with the cut side up the meat has the opportunity to brown a little adding a subtle depth and a heightened sweetness to soups.
So you you want to preserve water in the squash or if you want a cleaner flavor, then steam them. Otherwise, please roast you winter squash with the cut side up.