Preheat oven to 350 degrees. Line baking sheets with parchment paper or aluminum
foil. In a medium bowl, mix flour, baking powder, baking soda and salt. Set
aside. In large bowl, using a sturdy spoon or an electric mixer, lightly beat
eggs, sugar and vanilla. Gradually add dry ingredients to egg mixture at low
speed. Watch out for flying flour if too much is added at once. Dough will be
dry and crumbly. Mix until dough begins to take form. Mix in ginger and white
chocolate.
Scrape dough onto a work surface lightly coated with flour. Lightly coat hands
with flour and knead briefly until dough is soft and not sticky (about 8 to 10
times). Divide dough into 2 pieces. Shape each piece into a log about 10 inches
long, 2 inches wide and 1 inch high. Carefully transfer logs to baking sheet,
placing logs 4 inches apart. Bake for 35 to 40 minutes until well risen, lightly
browned and firm to the touch. Remove from oven and reduce temperature to 325
degrees. Cool cylinders on baking sheet for 10 minutes until warm. Peel off
paper or foil and transfer logs to cutting board. Using a serrated or sharp
knife, cut diagonal 1/2-inch slices. Use a firm and fast cutting motion to
prevent crumbling. Lay biscotti flat on baking sheets. You will need two sheets
to fit all the biscotti. Return to oven and bake until golden, firm and very
dry, about 20 to 25 minutes. Cookies might be slightly soft in center but will
harden as they cool. Let stand 2 minutes. Remove from baking sheet to rack. Cool
completely before storing or biscotti may become soggy.
