In the bowl of a stand mixer, add the fine granulated sugar and zest the oranges over it.
Using your fingers, rub the zest into the sugar until it resembles wet sand.
Add the salt, vanilla and butter and affix the paddle attachment and beat until creamed; about 3-4 minutes.
Add the egg and beat to combine, it’s ok if the mixture looks like it’s separated.
Add the flour and powdered sugar and beat until you have a thick, very sticky, dough.
Wrap the dough in plastic wrap to loosely seal then use a rolling pin to roll it out a bit more until it stretches the wrap. Hold it on its side and roll it on the counter like a wheel (this will even out the edges).
Chill the dough for at least 4 hours but preferably overnight.
The next day, line two greased cookie sheets with parchment paper and preheat the oven to 350 F.
On a floured surface, roll the dough out to about a quarter of an inch thickness. Use a cookie cutter to stamp out shapes and carefully place them on the prepared pan.
Squish the remaining dough together back into a ball and repeat the roll and cut process until you’ve used up all the dough.
Bake the cookies until *JUST* beginning to get golden on the edges, about 10 minutes (don’t over bake them, they’ll turn crispy instead of tender).
Out of the oven, let the cookies completely cool. At this point the cookies can be placed in an airtight container and reserved for glazing and serving later.
Make the glaze by whisking together all the ingredients in a bowl; if the glaze is thick, add more orange juice, if it’s thin, add more powdered sugar, you’re looking for the consistency of elmer’s glue.
Dip the completely cool cookies face down into the glaze. Alternatively, spoon the glaze into the center of the cookies and use the back of a spoon to spread it around. You can also dip the whisk in the glaze then quickly drag it over the cookies in a zig zag motion to create a pretty pattern. Let the glaze ‘set’, this will take around 20 minutes depending on the thickness of the glaze layer.
The cookies are ready to eat or they can be stored in one layer (so as not to mess up the glaze) on a plate for later.