"Biscotti" is Italian for "twice baked", and thus the reason these cookies are so deliciously crunchy. The flavors of "Constant Comment" come through in both the cookie dough and the icing, which gets drizzled over each biscotti for a sweet finish.
Preheat oven to 375 degrees and place rack on middle setting. Line a large baking sheet with parchment paper. In a measuring cup, steep tea bags in hot water for 5-7 minutes. Thoroughly squeeze tea bags into cup before discarding. Place tea into a small saucepan and boil until liquid is reduced to ½ cup. In a large bowl, combine butter, sugar and eggs. With an electric mixer, beat on high speed for one minute. Add ¼ cup plus 2 tablespoons of the prepared tea (reserving the remaining 2 tablespoons for icing) to butter/sugar/egg mixture, and mix to combine. In a smaller bowl, combine flour, baking powder, and salt and stir to combine. Add to wet mixture a little at a time, and stir to combine. Add white chips and stir to evenly incorporate. Turn dough onto a prepared pan and with lightly floured hands, form into a log, approximately 16 inches long by 3 inches wide and ½ inch high. Bake for 20 minutes, remove from oven. Allow to cool for 5-7 minutes. Cut each log crosswise into ½ inch wide slices. Lay each slice on its side on the baking sheet, and return to oven for an additional 20 minutes. Cool completely on a rack, and prepare icing. To make the icing, combine 1 cup powdered sugar and 2 tablespoons of the remaining tea. Stir to combine. Once biscottis are cooled, drizzle icing is a zig-zag pattern over each one.