Pour 1/2 of the chocolate pudding into the premade crust & spread evenly.
Mix thawed cool whip into the rest of the pudding mixture until completely combined.
Evenly spread pudding/cool whip mix on top of the pudding already in the crust.
Chill pie in refrigerator for 1-2 hours or until well set.
After pie has fully set, remove from refrigerator and top with marshmallows. Place pie under a hot broiler for 3-5 minutes, or until the marshmallows have been browned. Remove immediately and return to refrigerator for a few minutes to re-set the pie. Remove from refrigerator to serve.