In a food processor, combine wafer cookies with brown sugar, canola oil, and 1 teaspoon espresso dissolved in water. Process until ground. Press mixture into a 9-inch pie pan.
Place marshmallow cream into a large bowl and fold in the non-fat frozen whipped topping. Divide the mixture into 2 separate bowls. Fold cocoa powder into 1 of the bowls and then spread over crust. Fold 4 teaspoons espresso dissolved in water into the second bowl and then spread over filling.
Refrigerate for 2 hours or until set. Slice with a hot, wet knife. Top with shaved chocolate.