Heat the oven to 350 F and line two baking sheets with parchment paper
In the work bowl of a stand mixer, or in a large bowl with a hand mixer, combine the butter, sugar, brown sugar, golden syrup (or honey), and vanilla. Beat on low-speed until just combined and smooth, about 1 minute.
Add the flour, baking soda, and salt and mix on low-speed until just combined, about 20 seconds, then add the chopped chocolate and cacao nibs and mix to combine thoroughly, about 10 seconds more.
Turn the dough out onto a lightly floured surface and divide into six equal pieces. Roll each piece into a rope about 15-inches long. Place two ropes on a baking sheet and bake for 8 minutes so the cookies can spread, then sprinkle the coarse sugar over the bars and continue baking to 8 to 10 more minutes, or until the cookies are golden brown but not dark.
Remove from the oven and cool for 1 minute, then with a pizza cutter or very sharp knife slice each bar vertically into ½-inch cookies. Allow the cookies to cool completely on the pan.
Recipe by Evil Shenanigans at http://evilshenanigans.com/2014/02/cacao-nib-cookies/