Light as a feather and slightly chewy, these meringue-based cookies are a snap to make. Humidity will make them soggy, so be sure to store completely cooled cookies in an airtight container at room temperature.
Position two racks as near to the middle of the oven as possible, and preheat the oven to 325 degrees F. Line 2 rimmed baking sheets with parchment paper or Silpat liners.
Place the egg whites in a medium-size, clean, dry bowl. Using an electric mixer, beat the whites at medium speed until they get foamy. Add the salt and continue beating until the whites hold very soft peaks. Then add the sugar gradually, beating on high speed until the whites are stiff and shiny, 1 to 2 minutes. Fold in the orange zest, vanilla, dates, and pecans.
Drop the cookie batter by teaspoonfuls onto the prepared sheets. Bake until the cookies are just set and have colored slightly, about 25 minutes. Allow the cookies to cool on the baking trays for 5 minutes, then carefully remove the cookies with a spatula to a wire rack to finish cooling. Store in an airtight container.