Preheat oven to 350 degrees. Line a large baking sheet with parchment paper.
In a large mixing bowl add softened butter and brown sugar. Using an electric mixer combine until blended.
Add two eggs one at a time. Add molasses and mix for one minutes.
Add flour, baking powder, spices and salt. Mix for about 3 minutes on medium low until a soft dough forms.
Place on cookie sheet and shape into log that is 11" long and 1/2" thick.
Bake at 350 degrees for 20 minutes. Cool for at least 15 minutes.
Using a serrated knife carefully cut into 1/2" slices.
Arrange slices onto baking sheet. Second bake time: For a crispier cookie bake 10 minutes on each side. For a softer but still firm cookie, bake for 5 minutes on each side.
For Chocolate Drizzle - add white chocolate chips to a microwave safe container like a measuring cup. Melt on high for 35 seconds. Stir. Heat on high for another 35 seconds and stir. Continue stirring until chips are melted.
Using the tines of a fork drizzle on cooled biscotti. Put in fridge to firm up the chocolate quickly if desired.