Pastas are nutrient and calorie dense. Raman Noodles have 400 calories per serving - though they label it as "200 calories" and say that their are 2 servings in a pack. Eat the whole thing.
There are some Ensure type "shakes" that are designed for weight gain. They're in the pharmacy area at Walmarts and other retailers. Walmart even has a lower cost house brand.
Why can't you eat the ice cream? Lactose issues? Try
Lactaid or one of the many other similar products. They come in tablet form and break down the lactose in dairy food that gives many people problems, particularly as we age.