If you want something that will digest slowly - cottage cheese would be better than having whey.... If the protein powder is a casein powder then the difference will be less significant... The cottage cheese will also have some lactose in it - which, if you are trying to gain weight, may be more beneficial than protein alone.
Ideally - you should also consider adding some other things to the meal such as a carb source such as higher fructose fruits/berries (to help maintain liver glycogen and body glucose over night without having a huge effect on blood glucose and insulin levels) as well as some fiber and healthy fats (to help delay gastric emptying and decrease the rate of digestion.