Biscotti are twice-baked Italiany cookies. The double dose of oven time makes them less perishable than their moist relatives, the once-baked cookies. In this case dry and crunchy are desirable traits.
There are lots of variations for biscotti but I wanted to make one that featured almonds since that’s a traditional ingredient. We also just happened to have some crystallized ginger in the cupboard so when I stumbled upon a recipe that utilized both on Epicurious it seemed like a no-brainer.