In a heavy-bottomed saucepan, whisk together the brown sugar, cornstarch and
1/4 teaspoon salt. Whisk in the milk, then whisk in the egg yolks. Stirring constantly,
bring the mixture to a simmer (about 8 minutes). Simmer, whisking, until thickened,
1 to 2 minutes. Whisk in the pumpkin and ginger and cook, stirring, for 1 minute.
Transfer the pumpkin mixture to a bowl and stir in the vanilla. Place a piece
of parchment paper directly against the surface.
Refrigerate the pastry cream until
chilled, at least 2 hours and up to 2 days.