Adjust the oven rack to the middle position, pre-heat the oven to 350ºF (180ºC) and line a large baking sheet with parchment/baking paper.
Add the sugar and orange zest to a large bowl, and use your fingertips to rub the zest into the sugar.
Add the softened butter and vanilla, and mix well with a wooden spoon or rubber spatula until combined.
Sift in the gluten free flour blend, cornstarch, xanthan gum and salt. Mix it all together until you get a fairly dry mixture.
Add the orange juice and mix well until the cookie dough starts coming together. Knead until it comes together in a smooth ball.
Roll out the cookie dough between two sheets of parchment/baking paper into a rough rectangle about 1cm thick and just over 12cm wide.
Trim the cookie dough rectangle so that it's 12cm wide, and cut it into about 1cm wide cookie sticks.
Carefully transfer the cookie sticks onto the lined baking sheet.
Bake at 350ºF (180ºC) for about 15-18 minutes or until they’re light golden all over.
Allow to cool on the baking sheet for about 10 minutes, then transfer them to a wire cooling rack to cool completely.
If your melted chocolate is too thick, add 1-2 teaspoons of melted coconut oil to loosen it up.
Transfer the melted chocolate into a narrow container and dip the cookie sticks into the melted chocolate.
Transfer the chocolate-dipped cookie sticks onto a lined baking sheet.
For extra decoration, use remaining chocolate to pipe zig-zag lines over the chocolate-dipped end of the cookie stick.