Mix pudding and milk, stir as box directs. Add cool whip. Place 15 crackers squares on bottom of a 13x9" pan. Add 1/2 of the p8dding mix. Place another 15 crackers on top. Add remaining pudding. Top with another 15 crackers. Then mix toether the cocoa, butter and sweetened condensed milk. Blend over heat until together. Place it on top of the crackers.