Preheat oven to 325 degrees and line 2 baking sheets with parchment paper.
Measure out the ingredients. Add the eggs to a small bowl with the lemon zest and vanilla extract. Add the flour and baking powder in a bowl and lightly stir with a fork to blend.
Beat the butter and sugar on medium until blended. Scrape down the sides and bottom of the bowl and add in one egg yolk at a time, continue beating.
Turn the mixer to low and add in the flour and mix until the ingredients are incorperated.
Using a spatula, fold in the sweetened cranberries and pistachios.
Divide the dough in half and form two logs (about 15 inches long and 2 inches wide) on a baking sheet lined with parchment paper.
Bake for 15 minutes in a 320-degree oven.
Next, use a bread knife or another serrated knife to cut the logs into clean, smooth slices about 1/2″ thick. Slice the logs at an angle if you want a coffee shop biscotti’s long slices. Or you can slice straight.
Place the slices on a baking sheet and bake for another 10 minutes until lightly golden brown.
Ensure that the biscotti cool on a wire rack after the second bake so they can crisp completely.
Melt white chocolate chips and dip the end of each biscotti into the chocolate. Let the chocolate harden.