Preheat oven to 350 degrees F. Mix together the flour, sugar and baking powder. In a separate bowl, mix together the eggs, candied peel, zest, and orange juice. Mix the dry ingredients into the egg mixture until mixed, then add the pistachios. Dump onto a lightly floured surface and using floured hands gently knead for a minute or two and then divide into two pieces. Shape each piece into a log and place the logs onto a lightly greased baking sheets. Bake for about 20 to 25 minutes until lightly browned and firm to the touch, cool ten minutes, then slice the logs with a serrated knife into 1/2 inch slices. Lay these slices cut side down and then return to the oven to bake another 5 to 7 minutes. Cool, then store in an airtight container.