Preheat the oven to 350 degrees F.
Halve the squash and scrape out the seeds. Place the squash cut-side down in a roasting pan. Add 2 to 3 inches of water and roast
the squash until it is very tender, about 30 minutes. Allow the squash to cool completely then mash
or puree it in a food processor
. Measure 2 cups of the puree and reserve.
Combine the milk and sugar in a saucepan
. Scrape the seeds from the vanilla bean
into the milk then bring it to a simmer
over medium heat.
Meanwhile, beat the egg yolks in a large bowl. When the milk
reaches a simmer, temper the eggs
by gradually whisking 1/2 cup of the hot milk mixture into the yolks. Repeat until half the milk is incorporated, then whisk
in the remaining milk. Stir the reserved squash puree into the ice cream base then strain
the base through a fine sieve
into a bowl set over an ice bath.
Chill the ice cream base completely then process it in an ice cream
maker according to the manufacturer's instructions. Spoon the ice cream into containers and freeze until firm. Serve the ice cream topped with spiced pumpkin seeds