The chocolate biscotti recipe in Cookies and Brownies is a perfect answer for those folks who aren’t big sweets eaters. The espresso gives the biscotti a grown-up flavor, and cocoa powder, rather than chocolate, means these aren’t as sweet (or sticky) as brownies or cookies.
I tested this biscotti recipe using two different kinds of cocoa powder, and making the appropriate substitutions for baking powder and baking soda (variations are listed in the recipe below). The differences were subtle, and mostly affected the taste of the biscotti.