To make pumpkin purée from scratch, cut a medium-small sugar pumpkin in half. Scrape out the insides (reserving the pumpkins seeds to toast) and discard. Line a baking sheet with Silpat or foil. Place the pumpkin halves cut side down on the lined baking sheet and bake at 350°F until a fork can easily pierce them, about an hour to an hour and a half. Remove from oven, let cool, scoop out the pulp. Alternatively you can cut the pumpkin into sections and steam in a saucepan with a couple inches of water at the bottom, until soft (strain before using). If you want the purée to be extra smooth, press the pulp through a food mill or chinois.