Spray a 2 quart bowl with nonstick cooking spray. Line the bowl with plastic wrap. Cut the cake into 1/2 inch thick slices. Cut each slice diagonally in half, forming triangles. Line the bottom and sides of the prepared bowl with the cake triangles. Brush some of the Cooled Chocolate Chai Tea over the cake triangles that are lining the bowl. Reserve the extra triangles and set aside. Stir the chocolate in a large metal bowl set over a saucepan of simmering water until the chocolate melts. Allow the chocolate to cool slightly. Using an electric mixer, beat 1 cup of cream in another large bowl until it is thick and fluffy. Fold 1/4 of the whipped cream into the chocolate. Fold half of the remaining whipped cream into the chocolate mixture. Fold in the remaining whipped cream. Spread the chocolate cream over the cake, covering completely and creating a well in the center. Cover and refrigerate if not assembling cake right away. In another clean large bowl, add the remaining cream and 1/2 teaspoon of chocolate chai tea. Using an electric mixer with clean beaters, beat on medium speed and gradually add the powdered sugar. Beat until firm peaks form. Fold in the shaved chocolate. Spoon the cream mixture into the center of the well of the filling. Brush the remaining cake slices on one side with chocolate chai tea and place them, tea side down, over the filling, covering the filling completely, trimming to fit, if necessary. Cover the cake with plastic wrap and refrigerate 3 hours. Remove from bowl, and invert onto a serving platter. Sprinkle with cocoa powder. Serve chilled