Make the crust: Combine the flour, sugar and a pinch of salt in a large bowl. Mix in the cold butter with a pastry blender or your hands until the mixture resembles coarse crumbs. Work in 3 tablespoons ice water until the dough holds together without being too sticky. If it's still crumbly, add more ice water, 1 teaspoon at a time. Form into a ball, wrap in plastic and refrigerate for at least 30 minutes.
On a floured surface, roll out the dough into an 11- to 12-inch circle with a floured rolling pin. Ease into a 9-inch pie pan; press firmly into the bottom and sides. Trim the excess dough, then pinch the edges. Refrigerate until ready to fill.
Place a baking sheet on the bottom oven rack and preheat to 375. Make the filling: Whisk the pumpkin in a bowl with the butter and a pinch of salt. Whisk in 3 eggs and the sugar.
Stir in the cream, cinnamon and nutmeg. Pour the mixture into the pie shell. Lightly beat the egg white, then brush onto the pastry edges. Carefully place the pie on the preheated baking sheet, lower the oven temperature to 325 and bake until the pie is set but still jiggles slightly, about 50 minutes. Let cool completely.
Meanwhile, make the topping: Toast the pecans on a baking sheet in the oven for about 10 minutes; cool. With a knife or food processor, coarsely chop the pecans, cranberries and cookies; sprinkle over the cooled pie.