Pre-heat the oven to 350ºF. Line a baking sheet with a piece of parchment paper and set aside.
In a large mixing bowl whisk together the flour, sugar, baking powder, zest, salt, and nuts. Set aside.
In a medium mixing bowl whisk together the eggs, vanilla, and orange juice. Add the wet ingredients to the dry and mix to combine.
Lightly dust your hands with flour and turn the dough out onto the prepared baking sheet. Shape the dough into a log about 1-inch thick and about 4-inches wide. Bake the log until puffed and golden brown, 33 – 35 minutes. Cool the log completely.
When the log has cooled, slice cookies that are about 1/4-inch thick and arrange them cut side down on the prepared baking sheet. Bake the cookies a second time until golden brown and dry, about 35 minutes, rotating the sheet halfway through baking. Cool completely before serving. Store the cookies in an airtight container at room temperature for up to 7 days.
OPTIONAL: If you really want to gild the lily on these, melt 1 1/2 cups of semisweet chocolate chips and dip the bottom sides of each cookie in the chocolate. Place them onto a baking sheet lined with parchment paper and refrigerate for 10 minutes to set the chocolate.