Made some brown sugar shortbread, and did not like the result. It felt dry, like there was sand in the mix, but it also had a chew in the middle, probably because of the brown sugar. The next day the texture improved (I guess the cookie took on moisture), but it was still no the tender shortbread I like. Perhaps whipping the butter - thus basically trying to make the volume larger, but also drying the dough via brown sugar hogging up all the moisture - is not a good combo.
Guess if I am to use brown sugar, make sure whatever you are baking has a good amount of moisture it can keep, so the result, moist + chewy, which is why we like stuff like brownies and american cookies, is obtained. Dry and chewy not so much.
But what do I know (more by the day, hopefully).
EDIT: I also put half a teaspoon of cloves, ginger and cinnamon into the cookie dough, but in the end they were almost imperceptible. Probably because they were bound up in the dough, and could not thus hit my receptors in the nose, and there was no moisture to transport them. Probably should use these spices in stuff that emits a lot of vapors instead, so moist and warm stuff.