In a medium bowl whisk together the all-purpose and whole-wheat flours, the baking powder and salt. In a large bowl beat together the sugar, eggs, oil, orange zest and vanilla extract until well combined. In batches add the dry ingredients until the mixture forms a dough. Beat in the cherries, almonds and chocolate.
Transfer the dough to a floured work surface and knead several times. Shape into a log about 10 inches long and 3 inches wide. Transfer to a parchment-lined baking sheet and bake for 25 minutes. Transfer to a wire rack and let cool for 15 minutes. With a serrated knife, cut 1/2-inch diagonal slices. Arrange cut-side down on the baking sheet and bake for 10 minutes. Turn the cookies over and bake the biscotti until golden, 5 to 10 minutes longer. Transfer to a wire rack to cool.