steamed bun可数吗

3.She relishes the mornings when she can walk Yunhao to school , stopping on a recent morning to buy him a steamed bun for breakfast .
每一个能送孩子上学的早晨都给她带了莫大的幸福，就在几天前，她还在路上给儿子买了一个包子当早点。
由此可将，是可数的