Preheat oven to 350 degrees. Line a baking sheet with parchment paper.
Mix the sugar and orange zest in a small bowl using a fork. This will release the flavor into the sugar and will not clump when mixing.
In large mixing bowl, beat butter and the orange sugar mixture until combined.
Add in eggs and vanilla extract and mix until combined.
Whisk the baking powder with the floru and slowly add flour and baking powder to the wet ingredients, blending well after each addition.
With a rubber spatula or wooden spoon, fold in the chopped dried cranberries. *TIP: I like to coat the cranberries with a teaspoon of flour to help them not stick together.
On a parchment paper lined baking sheet, shape dough into a 12 inch by 4 inch log, patting evenly. TIP: Lightly coat hands with flour to help the dough not stick.
Bake for 25-30 minutes. Remove from oven and cool for 15 minutes.
Slice biscotti into ¾ inch slices with a sharp serrated knife.
Arrange cookies upright on baking sheet and return to oven. Bake an additional 20 minutes.
Remove and cool completely on a wire rack.
In small bowl mix zest of one orange with 1 tablespoon of sugar.
Melt the white chocolate wafers according to the package directions. Drizzle over on cooled biscotti and immediately sprinkle with orange sugar.
Allow to set (about 15 minutes). Store in air tight container.