Completely crush cookies by hand in a large bowl. Add the cocoa and melted butter or margarine. Slowly add the milk and stir the mixture. (It should not become too runny or too stiff.) Put this mixture into a glass cake pan and spread it out by pressing down with a spoon. Put all the ingredients for the pudding into a pot and cook until it becomes thick, stirring constantly. While the pudding is still hot, spread it out evenly over the cookie mixture. Before the pudding cools, sprinkle the cocoa on top.