Preheat your oven to 325 degrees F (160 C).

In a large bowl, cream the softened butter and granulated sugar together using an electric mixer until light and fluffy, about three minutes.

Integrate the vanilla extract and add the eggs one at a time, ensuring each is well mixed before adding the next.

In a separate bowl, whisk together the flour, baking powder, and salt. Gradually fold the dry ingredients into the wet ingredients in two parts, blending until combined.

Gently stir in the pistachios and candied orange peel.

Divide the dough in half and shape each portion into a loaf approximately 7 inches by 5 inches.

Place the loaves on a parchment-lined cookie sheet and bake for 25 to 30 minutes, or until they achieve a light golden brown hue.

Allow the loaves to cool completely. Once cool, slice the biscotti into half-inch thick pieces.

Return them to the oven for a second baking, allowing 13 to 15 minutes at low heat, flipping halfway through.

As the biscotti cool, melt the white and dark chocolate separately in the microwave.

Dip one half of the biscotti in the chocolate, letting any excess drizzle off before placing them back on the parchment.

Sprinkle chopped candied orange peel and pistachios atop the chocolate before it sets.