Is this textured bun still "mantou"?
The Chinese mostly call it "花卷" in daily life but you might regard it as a variant of "馒头" as well, if you apply the concept of "馒头" broadly. It's just that it more usually comes with some flavoring compared with 馒头 which can be plain. Apparently there's a Wikipedia entry for it https://en.wikipedia.org/wiki/Mandarin_roll