I also give only Japanese brands 既米餅 to Little Pumpkin. They melt in the mouth very quickly. Wakado(和光堂), Meiji and Pigeon all have 米餅 - no wheat. Re-on have many many choice, and they do delivery or you can visit them at their warehouse in Chai Wan - many things to see on display there.
I tried giving him Heinz before, but notice that they have wheat, so I stopped immediately.