In a large bowl, sift together flour, cinnamon, and salt.
In another bowl, beat butter, granulated sugar, beaten egg, and orange zest with an electric mixer at medium-high speed until the mixture is pale and fluffy, approximately 3 minutes. Reduce speed to low and add flour mixture in three (3) batches, mixing until dough just comes together in clumps; mix in pistachio nuts and cranberries.
Gather and press dough together into a log shape. Using a sheet of plastic wrap or wax paper as an aid, form each piece of dough into a log about 1 1/2 inches in diameter. Square off long sides of each log to form a bar. Sprinkle decorative sugar over the bars and press into the sugar, coating well. Refrigerate, wrapped in plastic wrap, until very firm, at least 2 hours.
Preheat oven to 350 degrees F. Put oven rack in upper and lower thirds of oven. Line two (2) large baking sheets with parchment paper or silpads.
Using a sharp knife, cut each bar crosswise into 1/4-inch thick slices, rotating bar after cutting each slice to help keep the square shape. NOTE: If dough gets too soft to slice, freeze bars briefly until firm. Arrange cookies about 1/2-inch apart on the lined baking sheets.
Bake cookies, switching position of baking sheets halfway through baking, until edges are pale golden, approximately 10 to 15 minutes. Remove from oven and transfer cookies to a wire rack to cool completely.
Dough bars can be refrigerated up to 3 days or frozen, wrapped in plastic wrap and then aluminum foil, for 1 month. Thaw frozen dough in the refrigerator just until dough can be sliced. Cookies can be kept in an airtight container at room temperature for 5 days.
Variation: Use dried apricot in place of the cranberries.
Pistachio Cranberry Icebox Cookie Recipe: https://whatscookingamerica.net/cookie/pistachiocranberrycookies.htm