Preheat the oven to 400 degrees  F.

Lightly grease an 8-inch pie plate. 

Make the pastry: In a food processor, place the 8 tablespoons of butter, 1 ¼ cups flour, and ¼ teaspoon sea salt. Pulse for a couple of minutes, until a crumbly meal forms. Add the ice water. Pulse again, until a dough forms. Gather into a disk. Turn pastry onto a floured board. Don’t handle it too much. Roll out into a thin round circle. 

Make the crumb topping: In a large mixing bowl, place the 1 ½ cups of unbleached white flour, cinnamon, nutmeg, ⅛ tsp sea salt, and brown sugar. Cut in the butter with a fork until you have a crumbly mixture.

Make the wet bottom: In a bowl, place the pumpkin purée, molasses, and maple syrup. Mix well. Add the boiling water and stir well.

Carefully transfer the pastry into the prepared pan. Gently press it into the pan. Trim the edge. You can fold and crimp the edge depending on the design you prefer. 

Pour one-third of the molasses mixture on the bottom of the pastry, then evenly distribute one-third of the crumb mixture by sprinkling over the molasses mixture. Repeat this process, using another third of the molasses mixture, then another third of crumbs, and the last third of the molasses mixture. Finally, sprinkle the remaining crumb topping on top of your pie. 

Bake at 400 degrees F. for 25 minutes, then lower to 350 degrees F. for another 30 minutes.

Let the pie cool for a couple of hours before slicing and serving.