Line a standard loaf pan with multiple layers of plastic wrap, leaving several inches over the sides to wrap the top.
Sift the 1/3 cup powdered sugar and 2 Tablespoons cocoa powder into the bowl of a stand mixer or large mixing bowl. Pour in the 1 1/2 cups heavy whipping cream; whip on high speed until soft peaks form. Add in the 1 teaspoon vanilla and continue to beat until thickened.
To assemble the dessert, place a single layer from 1 package chocolate wafer cookies* see tips in the bottom of the loaf pan. Add a layer of the chocolate whipped cream. Repeat the layers until you until you reach the top of the pan; end with a layer of chocolate whipped cream.
Cover the top of the dessert with the overlaying plastic wrap. Place in freezer for 2 hours, then remove to refrigerator to chill at least 12 hours prior to serving (alternately, can leave in freezer if serving frozen).
When ready to serve, invert the loaf pan onto a platter or large plate and remove the plastic wrap. Sprinkle the top of the dessert with crushed chocolate wafer crumbs. Cut the dessert into slices.
Notes
Tips:
For chocolate wafer cookies, use the following:
Chocolate ice cream sandwich wafers (I found mine at a restaurant supply store)
Oreo thins
Chocolate graham crackers
Homemade cookies (make sure they are thin)
Chill your bowl and beaters prior to whipping the heavy whipping cream
Chill up to 3 days; freeze up to 45 days
If serving this dessert frozen, allow to sit at room temperature for about 15 minutes to allow to easier cutting