Pumpkin Crème Fraîche Sherbet

I made this 3x, 1st and 3rd were great (sugar pie pumpkin and butternut squash, respectively), 2nd time (using a sunshine squash instead of a sugar pie pumpkin) was bad. Awesome addition to the Sorbet Chronicles, when it works... The pic is from the 3rd batch, done early summer when peaches were towards being in season.

Pumpkin Crème Fraîche Sherbet
1 small pumpkin, ~8" diameter
1c sugar
pumpkin pie spice
1t salt
2c heavy whipping cream, cultured with buttermilk to make crème fraîche
1/4 c sugar
1T vanilla

Cut pumpkin in half, scoop out seeds, put in a pot with a little water, cover, steam for 30 min or so
Let it cool, then scrape flesh off of shell
Put in a small pot with 1c sugar and alot of pumpkin pie spice, salt, cook for 30 min or so
Culture the cream with a couple of tablespoons of buttermilk for 24 hours at room temperature
Whip cream to peaks, then add sugar and whip a little more, mix in the pumpkin and vanilla