In a large saucepan, whisk together the cream, brown sugar, egg yolks, spices and salt.
Over medium heat, cook the custard, whisking constantly but slowly. Cook for about 10 minutes, until the mixture is hot and steaming, but not boiling. Remove from the heat.
Whisk in the pumpkin, vanilla and bourbon.
Chill the custard until completely chilled, preferably overnight to allow the flavors to mingle.
Churn the chilled custard in your ice cream maker, according to the manufacturer's instructions, until it's a thick, soft serve ice cream consistency. Transfer to a lidded ice cream container and freeze until firm, about 6 hours.