1/2 cup finely chopped dried mango, apricots or cranberries
Preheat the oven to 350°. Line two baking sheets with parchment paper. In a small bowl, whisk the flours with the salt. In a medium bowl, using an electric mixer, beat the butter with the sugar at medium speed until light and fluffy, about 3 minutes. Beat in the egg and vanilla. At low speed, beat in the dry ingredients, pepitas and mango. Gather up the dough and knead a few times to form it into a ball.
Transfer the dough to a work surface lined with parchment paper. Using a lightly floured rolling pin, roll out the dough to a 10-by-12-inch rectangle. Transfer the dough (on the paper) to a baking sheet and freeze for 15 minutes, until firm but not frozen.
Using a sharp knife, trim the edges of the dough. Cut the dough into twenty 2-by-3-inch rectangles, then cut each in half to form 40 triangles. Arrange the cookies on the prepared baking sheets, spacing them 1 inch apart. Bake for 10 to 12 minutes, until lightly golden and set. Transfer the cookies to racks to cool.
The cookies can be stored in an airtight container for up to 1 week.