Preheat the oven to 300 degrees F. Make the crust: In the bowl of a food processor fitted with the metal blade, pulse the crackers and pecans until finely ground, 6 to 10 pulses. Add the melted butter and brown sugar and pulse to combine. Press the mixture into the bottoms and 1/2 inch up the sides of ten 6-ounce ramekins. Put the ramekins in a large baking dish or roasting pan and blind bake in the oven, 10 to 12 minutes. Remove and set aside to cool.

Make the custard: Combine 2 cups cream, the cinnamon, nutmeg and ginger in a saucepan over medium-high heat. Halve the vanilla bean lengthwise; scrape out the seeds with a knife, then add the seeds and pod to the saucepan. Bring to a boil and remove from the heat. Whisk the egg yolks with the granulated sugar in a bowl until the sugar is dissolved. Add the remaining 1 1/2 cups cream and the milk to the saucepan. Slowly whisk in the yolk mixture, then strain the custard through a sieve back into the bowl. Whisk in the pumpkin.

Divide the pumpkin mixture among the ramekins. Pour hot water into the baking dish, about halfway up the sides of the ramekins. Bake until the custard is starting to set but is still a little wiggly in the middle, 55 minutes to 1 hour. Remove from the oven; remove the ramekins from the water bath and let cool to room temperature. Cover and refrigerate at least 6 hours or overnight.

Lightly sprinkle the custard with turbinado sugar. Heat the sugar with a butane torch until caramelized. To get a thicker caramelized sugar crust, repeat, using just a light sprinkling of sugar each time. Let cool.

Photograph by Con Poulos