Preheat the oven to 350°F or 180°C and line a baking sheet with a parchment paper.
Whisk in the flour, cocoa powder, baking soda and baking powder in a bowl and keep it aside.
In a large bowl with add the butter and sugar and with a hand beater or stand mixer beat the sugar and butter for 2-3 minutes until light and fluffy.
Add the eggs one at a time and vanilla extract and continue to beat on low until just combined.
Now add the chopped crystallised ginger and dark chocolate chips stir until well distributed.
Add the flour mixture half cup at a time to the butter-egg mixture and slowly stir with a spatula to form a soft, sticky dough.
Divide it into 2 parts and make it into 2 equal sized loaf. Bake the loaf in the preheated oven for 25-30 minutes or until set.
Let the loaf cool slightly or until cool enough to handle. Transfer the loaf to a work surface and using a serrated knife, then cut logs on diagonal into 1/2 inch to 3/4 inch wide slices.
Now decrease the heat of the oven to 150° C.
Arrange the slices on the large cookie sheet and bake for another 25-30 minutes or until it looks nice toasted. Let the biscotti cool on the cookie sheet.
Store the biscotti in an airtight container, they will keep up to 6 weeks.