In a small bowl, combine flour, brown sugar, cinnamon, and salt. Mix in cooking oil until mixture is crumbly. Set aside.
In a medium bowl, combine boiling water and baking soda. Stir in corn syrup and molasses. Let mixture cool until just warm. Beat in egg.
On a lightly floured surface, use your hands to slightly flatten Pastry for Single-Crust Pie. Roll dough from center to edge into a circle about 12 inches in diameter. To transfer pastry, wrap it around the rolling pin. Unroll pastry into a 9-inch pie plate. Ease pastry into pie plate, being careful not to stretch pastry. Transfer filling to pastry-lined pie plate. Trim pastry to 1/2 inch beyond edge of pie plate. Fold under extra pastry. Crimp edge as desired. Do not prick pastry. Sprinkle 1/2 cup of the flour mixture over the bottom of pie shell. Carefully pour in the molasses mixture. Sprinkle remaining flour mixture evenly over pie.
Bake in a 375 degree F oven for 25 to 30 minutes or until mixture is set. Cool on a wire rack. Store in the refrigerator. If you like, garnish with fresh currants and thin lemon-peel curls before serving. Makes 8 servings.