In a food processor, combine granulated sugar and zest of 1 orange. Pulse until the zest is finely incorporated and the sugar appears moist, about 30 seconds.

To the orange sugar blend, add all-purpose flour, softened unsalted butter, salt, and optional orange extract. Pulse until they form a rough clump, approximately 1 minute.

Turn the dough out onto a lightly floured surface, knead gently until it holds together, about 1 minute. Divide into two logs, wrap in plastic wrap, and chill for 2 hours.

Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper.

Remove dough from refrigerator and slice each log into ½ inch thick rounds. Bake for 10-12 minutes until edges are golden.

Let cookies cool completely on a wire rack. Melt chocolate and dip each cooled cookie halfway into it, then place back on parchment paper.