Preheat the oven to 150°C.
In a mixing bowl, combine the butter and granulated sugar and beat, with a whisk or hand mixer, until light and fluffy, scraping down the sides periodically. Add the orange zest and beat in the
whole eggs one at a time. Stir in the vanilla.
Gently mix in the flour, baking powder and salt. Once the flour is incorporated, fold in the almonds, raisins and anise.
Divide the dough into two pieces. If the dough is sticky, dust your hands with a little flour. Roll the dough into two logs the length of a sheet tray and place on the tray. Beat the egg white with 1 tablespoon water in a small bowl. Brush the logs with the egg white and sprinkle with the demerara sugar. Bake until dark golden brown, slightly crisp around the edges and still a bit soft in the middle, about 30 minutes.
Remove from the oven to a cutting board and slice on the bias with a serrated knife while they are still warm. Slicing while warm will prevent crumbling.
Lay the biscotti back on the sheet tray(s), cut-sides down, and return to the oven until a little more golden around the edges, another 10 minutes. This will harden the biscotti but not make them like rocks.
Remove from the oven to a serving platter and serve with coffee or Vin Santo for dipping.
From Food Network Kitchens; after further testing and to ensure the best results this recipe has been altered from what was in the actual episode.
Recipe courtesy of Anne Burrell