Preheat oven to 300 Degrees F. Make crust: In food processor fitted with metal blade, pulse waffers and pecans until finely ground. Add butter and brown sugar and pulse to combine. Press mixture into bottoms and 1/2 inch up sides of ten 6-ounce ramekins. Put ramekins in a baking dish and bake 10 minutes. Remove and set aside to cool.
Make custard: Combine 2 cups cream, cinnamon and nutmeg in a saucepan over medium-high heat. Halve vanilla bean lengthwise; scrape seeds out, add seeds and pod to saucepan. Bring to boil and remove from heat. Whisk egg yolks with granulated sugar in a bowl until sugar is dissolved. Add remaining 1 1/2 cups cream and milk to saucepan. Slowly whisk in yolk mixture, then strain custard through a sieve back into bowl. Whisk in pumpkin puree.
Divide pumpkin mixture among ramekins. Pour hot water into baking dish, halfway up sides of ramekins. Bake until custard is starting to set, 55 minutes to 1 hour. Remove from oven; remove ramekins from water bath and let cool to room temperature. Cover and refrigerate atleast 6 hours.
Lightly sprinkle custard with turbinado sugar. Heat sugar with a butane torch until carmelized. Let cool.