In a food processor, pulse the granulated sugar and cranberries just until minced. You don't want a paste, just a crumble.
In the bowl of a stand mixer, beat the butter and icing sugar until blended. Add in the orange zest and cranberry mixture and mix again for 1 minute.
Add in the flour and mix on low speed just until dough comes together.
With floured hands knead the dough on a floured counter until smooth. Divide into 3 pieces.
On plastic wrap form each piece into a log. Either in a square or round form. Wrap tightly with plastic wrap and refrigerate at least 1 hour or unto 48 hours.
Preheat oven to 350℉.
Slice into ¼ inch thick slices and place 1 inch apart on parchment lined baking sheet.
Bake 15-18 minutes or just until starting to brown on the edges.
Store in a tin with waxed paper between the layers.
Recipe by Chateau Elma at https://www.chateauelma.com/cranberry-shortbread