To make the pie crust: Into a bowl, sift the flour, sugar,
baking powder, and salt. Add the shortening and blend until the mixture
resembles coarse crumbs. In a bowl, whisk together the egg and 2 tablespoons
of the ice water. Add the egg mixture to the flour mixture and toss to
combine, adding more water, if necessary, to form a dough. Chill the dough,
wrapped in plastic, until firm.
On a lightly floured surface, roll out the dough into a circle 1/8-inch thick
and fit it into a 9-inch pie pan. Crimp the edge, prick the bottom, and chill
while making the filling.