Whisk together the flour and salt and set aside for later.

In a medium sized bowl, cream together the butter and confectioners sugar. Add to this the orange zest and vanilla. Beat until light and fluffy, around 3-5 minutes, scraping down the sides of the bowl when needed.

Reduce the mixer speed to low and add in the flour, mix until just combined.

Using your hands, press the dough into a ball inside the bowl.

Turn out onto a lightly floured surface and knead the dough until is nice and smooth.

Roll the dough into log about 12 inches long and 2 inches in diameter. Wrap in waxed paper, tucking the ends under so the dough does not dry out and place in the fridge to chill for 30 minutes.

Preheat the oven to 325 degrees.

Line baking sheets with 2 layers of parchment paper. (*see note)

Slice the dough into 1/4 inch slices and place on prepared baking sheets.

Bake until firm. 13-17 minutes.

Allow to cool completely on wire racks, reserve parchment paper for later use.

Melt dark chocolate baking chips in a double boiler. Dip each cookie generously in dark chocolate and place back on parchment paper to dry.