Preheat the oven to 350°F.
On a lightly floured work surface, roll out the pie dough until it is about ⅛-inch in thickness. Line the pie plate with the dough, being careful not to stretch it as you do. Trim any excess dough, leaving a 1-inch overhang around the border of the plate. Fold the overhang over and crimp with your fingertips to form a decorative edge. Prick the base of the dough all over with a fork and line with parchment paper. Fill with dry beans or baking weights and bake for 10-15 minutes or until the pie dough is completely cooked and nicely golden. Remove from the oven and allow to cool.
Fill your cooled pie shell with the chocolate pudding. You can make your pie until this point and keep in the fridge until ready to serve. Before serving, whip the cream until stiff peaks form and generously spread all over the pudding filling. Garnish with a light sprinkling of cocoa powder.