Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
In a mixing bowl, whisk together the flour, baking powder, and salt. Set aside.
In a large bowl, cream the softened butter and sugar together until light and fluffy.
Beat in the eggs one at a time, followed by the vanilla extract, mixing well after each addition.
Gradually mix in the dry ingredients until just combined.
Fold in the cranberries and chopped pistachios until evenly distributed throughout the dough.
Transfer the dough onto a lightly floured surface and shape it into a log about 12 inches long and 3 inches wide.
Place the log on the prepared baking sheet and flatten the top slightly.
Bake in the preheated oven for about 25-30 minutes, or until the log is lightly golden and firm to the touch.
Remove from the oven and let it cool for about 15 minutes on the baking sheet.
Once slightly cooled, carefully transfer the log to a cutting board and slice it diagonally into 1/2-inch thick pieces.
Arrange the slices cut-side down back on the baking sheet.
Bake for an additional 10-15 minutes, until the biscotti are golden and crisp.
Remove from the oven and allow to cool completely on a wire rack.
Notes
Arrange the biscotti in a decorative container or on a platter. Pair with a small dish of chocolate or caramel sauce for dipping, and garnish with a sprinkle of chopped pistachios on top.