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.
Preheat your oven to 425°F. Beat the eggs in a large bowl. Mix in the brown sugar, white sugar, salt, spices-cinnamon, ground ginger, nutmeg, ground cloves, cardamom, and lemon zest.
Mix in the pumpkin purée. Stir in the cream. Beat together until everything is well mixed. Pour the filling into an uncooked pie shell. Bake at a high temperature of 425°F for 15 minutes. Then after 15 minutes, lower the temperature to 350°F. Bake for 45 to 55 minutes more, or until a knife inserted in the center comes out clean. (About half-way through the baking, you may want to put foil around the edges or use a pie protector to keep the crust from getting too browned.)
Cool the pumpkin pie on a wire rack for 2 hours. Note that the pumpkin pie will come out of the oven all puffed up (from the leavening of the eggs), and will deflate as it cools.
Serve with whipped cream.