Adjust the oven rack to the 2nd level position (just above center) and (on the same rack), place a baking sheet, jelly roll pan, or baking steel. Preheat the oven to 400ºF.
In a medium size mixing bowl, combine all ingredients for the bottom filling and set to the side.
For the top batter, combine the all-purpose flour, light brown sugar, vegetable shortening, and salt. Reserve 1 cup (147 g) for the crumb topping.
To the remaining batter mixture, add the molasses, hot water, and baking soda, mixing until just combined.
Pour the filling mixture into the chilled unbaked pie shell, followed by the batter. It's okay if the filling comes up the sides as you pour the batter in. Sprinkle the reserved 1 cup of crumbs over the top. Don't worry about the crumb topping sinking into the batter. It will remain on top.
Place the pie on top of the preheated baking sheet and bake for 400ºF for 15 minutes. Then reduce the temperature to 350ºF and bake for 30-35 minutes more. You may wish to add a silicone crust shield the last 15 minutes of baking to prevent the crust from over browning. The pie will appear jiggly, but will set as it cools. Transfer to a wire cooling rack to cool completely. Serve at room temperature or chilled with a dollop of whipped cream.