I was not able not taste the walnuts as the other ingredients were so flavorful. The original recipe uses 3/4 cup, but if you like walnuts there’s no harm throwing some more in there. You could also try the recipe with any other nut that you like. You may prefer to use cacao powder instead of carob power. I’m sure the recipe would work just as well with this substitution.
Store the balls in the fridge or freezer. If you store them in the freezer then you will need to thaw them for a few minutes before you eat them. I placed half in the fridge and half in the freezer. The freezer ones were firmer, but it wasn’t a huge difference to the ones that had been in the fridge. I did like the coolness of the ones from the freezer though. Supposedly they last for weeks in the fridge or freezer, but I couldn’t tell you for sure since they disappeared in my home within 24 hours