Can you tell me the story of Laxmichand and the sweet called khaja?

Certainly. This story from Chapter 28 illustrates Sai Baba's omniscience. A devotee named Laxmichand was on a pilgrimage and had a meal where a sweet called khaja was served. The next day, he deeply craved it, but it wasn't available. On the third day, in the masjid, Baba miraculously asked for a plate full of khaja to be brought as the food offering. When devotees brought two bowls of it, Laxmichand, who was very hungry, was able to eat it to his heart's content. This experience, where Baba fulfilled his unspoken desire, cemented Laxmichand's devotion and love for Baba.