Can you recount the story of how Sai Baba fulfilled Laxmichand's longing for khaja prasad?

Certainly. As recounted in Chapter 28, a devotee named Laxmichand was visiting Shirdi. After being served a little khaja (a sweet) as prasad one day, he developed a strong desire to have it again, but this eagerness remained unexpressed in his mind. The next day, in a display of his inconceivable knowledge, Sai Baba specifically ordered his devotees to bring him a "plate full of khaja" as a naivedya, or food offering. Following the afternoon arati, Baba announced his desire to have khaja prasad and instructed that it be served to everyone. In this manner, Baba miraculously fulfilled the unspoken desire of Laxmichand, who was also feeling very hungry at that moment, filling his heart with joy.