Preheat oven to 350 F and line a baking tray with parchment paper.
Cut pumpkins in half, scoop out seeds and place face-down on prepared baking tray.
Dock pumpkin surface with a fork and bake for 30 to 40 minutes, until tender. Cool, then scoop out pumpkin and purée until smooth.
Measure out 2 cups for custards, then refrigerate or freeze remaining.
Reduce oven temperature to 325 F and place 8 5-ounce ramekins in a baking tray with a lip. Heat whipping cream with scraped out seeds of vanilla bean until just below a simmer.
In food processor, purée sugars, egg yolks, ½ tsp cinnamon, ginger, allspice and brandy with reserved 2 cups of pumpkin.
Pour hot cream into pumpkin mixture until all has been added. Pour custard into ramekins and fill baking pan with boiling water (resting pan on oven door is easiest).
Bake for 30 to 35 minutes, until custards are set, but jiggle just slightly in the centre. Remove custards from pan, cool for 20 minutes, then chill for at least 4 hours.
To brulée custards, toss remaining ½ tsp cinnamon with turbinado sugar. Sprinkle onto custards, and caramelize with a butane torch (available at kitchen supply stores).
Chill for up to 2 hours or serve immediately.