rusk noun \ ˈrəsk \
a sweet or plain bread baked, sliced, and baked again until dry and crisp
biscotto noun bis·cot·to \ bi-ˈskät-ō \ plural biscotti \ bi-ˈskät-ē \
a crisp cookie or biscuit of Italian origin that is flavored usually with anise and filberts or almonds —usually used in plural
[Definitions from merriam-webster.com]
I sometimes buy biscotti at Whole Foods, but they don’t always have it.
The best bet for me, when I want a special treat to dunk into my morning coffee, is to go to British Pantry in Redmond. They usually have some of Ouma’s rusks, an import from South Africa.