Beat butter & sugar for about 3 minutes with an electric mixer, or until fluffy. Add egg and vanilla and beat 1 minute more. Mix dry ingredients in a bowl. Add gradually to the butter mixture, making sure not to beat too much, add in nuts and stir in cherries by hand. Divide the dough into thirds; roll each into a log.
Now for the sugars: Beat in the sugars; this is my preferred combination, because the relatively high water content of soft brown sugar keeps the dough moist and gives it a caramel flavour.