Roll out pie crust and fit into pie crust into plate; then freeze for 30 minutes.
In a small pot, mix together pumpkin puree, brown sugar, salt, cinnamon, ginger, cloves, allspice and maple syrup. Cook over medium-low heat, stirring often, for 10-12 minutes. Transfer cooked pumpkin mixture to another container and refrigerate to cool completely.
While pumpkin mixture is cooling, blind bake the crust. Preheat oven to 415 F (212 C) and remove pie crust from freezer. Let crust sit on counter for 15 minutes while oven preheats. Line pie crust with parchment paper and fill with pie weights, or fit a disposable aluminum pie plate inside the parchment (pressing down so the plate fits tightly inside the pie crust) and then place an inverted oven-proof bowl in the center to weigh it down. Bake on parchment-lined baking sheet until edges are set, 15-20 minutes. Remove parchment and pie weights or disposable pie plate and bowl (be careful – the bowl will be very hot!) and set aside. Prick the bottom of the pie crust with a fork, reduce heat to 350 F (176 C) and bake crust for 15 minutes more. In a small bowl, whisk 1 egg and add 2 teaspoons water. Brush a thin layer of egg wash all over the warm crust. Bake the crust for 2 minutes more.
While pie crust is baking, make custard. In a large bowl, gently whisk 2 eggs until light yellow. Add half and half, vanilla and cooked pumpkin mixture; whisk until just combined. Mixture should be smooth and all one color. Do not over-whisk.
When crust is done, pour filling into crust. Cover crust edges with pie shield or aluminum foil. Bake at 350 F (176 C) for 60 to 70 minutes, until custard is set and does not wobble.
Let pie cool completely on wire rack, about 4 hours. Serve and enjoy!