Preheat your oven to 350°F (175°C) to ensure even baking.
Line a large baking sheet with parchment paper to prevent sticking.
In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.
In a large mixing bowl, cream together the softened butter and sugar until light and fluffy.
Add the eggs and vanilla extract to the mixture, mixing until well combined.
Gradually add the dry mixture to the wet ingredients, mixing on low speed until just combined.
Gently fold in the almonds, pistachios, and dried fruits until evenly distributed.
Divide the dough in half and shape each half into a log on the baking sheet, leaving space between them.
Bake for 25-30 minutes or until golden brown, then cool for 10 minutes.
Slice the logs diagonally into 1-inch thick pieces.
Return the sliced biscotti to the oven and bake again for 15-20 minutes until crisp and golden.
Let the biscotti cool completely on a wire rack before serving.