Method:
Soak the dried cranberries in hot water and drain.
In an electric mixer, cream butter and sugar until light and fluffy. Add eggs, one a time, and blend until smooth. Add vanilla, flour, baking powder and salt. Mix until just blended (do not overbeat). Drain cranberries. Stir cranberries and pistachios into dough by hand.
Preheat oven to 325°F. Divide dough in half. On a lightly floured surface, knead dough a few times then shape into two long, slightly flattened, logs, about 2 inches wide and 12 to 14 inches long. Place both on a non-stick baking sheet a few inches apart. Bake for 25 minutes or until barely golden.
Let cool for 10 minutes. Slice logs on the diagonal about 1/2-inch thick. Return slices to the baking sheet and bake again for 20 minutes, turning halfway through baking, until golden brown. Let cool.
Biscotti will keep for several weeks in an airtight container.