In a large bowl, cream butter and sugar. Blend in eggs and anise extract. Sift together the flour, baking powder, and salt; stir into the egg mixture. Finally, stir in the candied fruit. Refrigerate dough for 1 hour.
Preheat oven to 325 degrees F (165 degrees C). Divide dough into 4 equal portions. Roll each portion into a log about 12 inches long. Place 2 logs per cookie sheet. Press down slightly and bake in the preheated oven for 25 to 30 minutes.
Remove from the oven and let cool on the pans for about 5 minutes. Slice diagonally into 1/2 inch thick slices. Place the slices cut side down on the baking sheet and return to the oven for another 16 to 18 minutes, or until lightly toasted. Cool on racks and store in airtight containers.