Preheat oven to 350 degrees. In a medium bowl, mix flour, sugar, pistachios, raisins, baking powder, and salt. In a small bowl, whisk together eggs and vanilla; add to flour mixture, and mix until combined (dough will be stiff; use hands if necessary to incorporate flour). Divide dough in half.
On a lightly floured work surface, roll each dough half into a 12-inch log; transfer logs to a baking sheet, and gently press to a 7/8-inch thickness. Bake until risen and firm, 15 to 20 minutes. Cool completely on baking sheet, about 30 minutes.
Reduce oven temperature to 300 degrees. On a cutting board, use a serrated knife to slice logs into 1/2-inch-thick slices. Lay slices in a single layer on baking sheet; bake until dry and just starting to brown, 15 to 20 minutes. Transfer to a rack to cool completely.
Store these cookies in an airtight container for up to one week. If the weather is damp and they lose some crispness, reheat in a 250 degree oven for five minutes.