Preheat the oven to 350F. Lightly grease (or line with parchment) one large (about 18" x 13") baking sheet.

In a medium-sized bowl, beat the butter, sugar, salt, flavor or extract, espresso powder, and baking powder until the mixture is smooth and creamy. Beat in the eggs; the batter may look slightly curdled. At low speed of your mixer, add the flour and chips, stirring until smooth; the dough will be sticky.

Divide the dough in half, plopping each half onto the prepared baking sheet. Using your wet fingers, shape each piece into a rough log about 12" long, 2" wide, and about ?" thick. Straighten the log, and smooth its top and sides.

Bake the dough for 25 minutes. Remove it from the oven, and allow it to cool on the pan anywhere from 10 to 25 minutes; just work it into the schedule of whatever else you?re doing in the kitchen. Using a spray bottle filled with room-temperature water, lightly but thoroughly spritz the logs, making sure to cover the sides as well as the top. Softening the crust just this little bit will make slicing the biscotti much easier.

Reduce the oven temperature to 325F. Wait another 5 minutes, then use a serrated knife to cut the log crosswise into ?" to ?" slices. As you?re slicing, be sure to cut straight up and down, perpendicular to the pan; if you cut unevenly, biscotti may be thicker at the top than the bottom, and they?ll topple over during their second bake.

Set the biscotti on edge on the prepared baking sheet. Return the biscotti to the oven, and bake them for 25 to 30 minutes, till they feel very dry. They?ll still feel a tiny bit moist in the very center, if you break off a piece; but they?ll continue to dry out as they cool. Remove the biscotti from the oven, and transfer them to a rack to cool.

To make the chocolate ganache: Combine the chocolate and half and half in a microwave-safe bowl, and heat for about 45 seconds, or until the cream is very hot. Stir until the chocolate melts and the mixture is smooth and creamy, reheating briefly if necessary. Stir in the espresso powder and hazelnut flavor.

Dip about 1/3 of each biscotti in the ganache. Lay dipped biscotti on a piece of parchment that you?ve sprayed with non-stick spray; a piece of waxed paper; or on a cooling rack. Allow biscotti to harden for several hours, or overnight, before wrapping for storage.

Yield: 3 dozen 3 ?" biscotti.