Finely chop the fresh cranberries and set aside.

In a food processor, combine unsalted butter, granulated sugar, and orange zest. Cream together until well mixed.

Add flour and vanilla extract to the mixture. Pulse the food processor about 10 times, then run it briefly until the dough forms a lump or two.

Gently fold in the chopped cranberries by pulsing just enough to mix them in, without over-processing.

Transfer the dough to a lightly floured surface and shape it until no longer crumbly.

Roll the dough into a log about 10-12 inches long. Wrap in plastic wrap and smooth the surface. Twist the ends to secure.

Chill the dough for at least 3 hours or overnight. Wrapping it in a towel helps keep its round shape.

Preheat oven to 350°F and line a cookie sheet with parchment paper.

Slice the chilled dough into 1/3 inch thick pieces. Place on the cookie sheet, leaving a two-inch gap between cookies.

Bake for 10-12 minutes, adjusting time for desired crispiness. Cookies should be pale on top and just golden on the bottom.

Allow cookies to cool on the baking sheet for a few minutes, then transfer to a cooling rack.