Add the butter to a large mixing bowl and mix on high speed for 4-5 minutes, until very light and fluffy.
1 cup salted butter
Mix in the vanilla, then add the sugar and orange zest. Beat again to combine, starting on a low speed and increasing once the sugar is partly mixed in.
Add the flour and mix until just combined. Gently mix in the cranberries by hand to incorporate.
2 cups white all-purpose flour, ½ cup dried cranberries
Turn the dough out onto a work surface and shape into a rough ball. Divide into two equal pieces, then shape each into a log about 7 inches (18 cm) long. Wrap well and chill for at least 4 hours, or up to 12 hours.
Once the dough has chilled, preheat the oven to 350°F (180°C) and line two baking sheets with parchment paper.
Coat the outsides of the logs with demerara (raw) sugar if desired. Cut into ¼-inch (.5 cm) thick cookies and place 1-inch (2 cm) apart on the baking sheets.
Raw sugar for coating
Bake for 10-12 minutes, until the edges of the cookies are just starting to turn lightly golden.
Cool for 5 minutes on the baking sheets before carefully removing to cool fully on wire racks. Make sure the cookies are cool before icing or storing.