Position a rack in the center of the oven and preheat to 350 degrees . Grease a 9-inch deep-dish pie pan. Using a food processor, grind the granola bars with 2 tbsp. brown sugar. Add the butter and egg white and pulse until the crumbs are moistened. Pat the mixture evenly onto the bottom and up the sides of the prepared pan. Bake until the edge is crisp and lightly browned, 15 to 20 minutes.
In a large bowl, whisk together the remaining 1/4 cup brown sugar, the pumpkin puree, eggs, cream, maple syrup, cinnamon, ginger and salt. Pour into the piecrust. Bake the pie until the center is almost set, about 45 minutes. Transfer to a rack to cool completely.