Cornmeal adds a nice crunchand hint of sweetness to thesedunkers. The salted macadamianuts balance out the richness ofthe white chocolate.
Preheat oven to 350 degrees. In thebowl of an electric mixer, beatflour, cornmeal, sugar, bakingpowder, and salt on low speed.Add eggs, vanilla, and butterand beat on medium until combined.Fold in cherries, nuts,and 1/2 cup white chocolate untiljust combined.
On a parchment-lined bakingsheet, form dough into a 13-inchlog; flatten to 3 inches wide and1 inch thick. Bake until just goldenand firm to the touch, about30 minutes. Transfer on sheetto a wire rack; let cool 20 minutes.Reduce oven to 300 degrees.
Transfer log to a cuttingboard. Using a serrated knife,cut crosswise into 1/2-inchslices. Arrange, cut-sides down,on another parchment-linedbaking sheet. Bake until firm tothe touch, about 30 minutes.Transfer biscotti on baking sheetto rack; let cool completely.Biscotti can made to this pointup to 1 week ahead and storedin an airtight container at roomtemperature up to 3 days.
Melt remaining 1 cup whitechocolate over a double boileror in a microwave. Transfer to acoffee mug. Dip sides of biscottiin melted chocolate on a diagonal;transfer to a baking sheetfitted with a wire rack. Let setslightly, 10 minutes; sprinkle withnonpareils. Refrigerate untilset, about 10 minutes. Finishedbiscotti can be stored in anairtight container at room temperatureup to 3 days.