I'm a big fan of the original, at Buca di Beppo and though this recipe is close, it is not quite right, to me. I tried this recipe and, while I thought the sauce was quite good, I would definitely recommend a couple of changes.

Start by cutting the amount of filberts and capers. I cut the capers in half and I still found it to be a bit much. I would probably quarter the amount called for, by the recipe. I used the correct amount of filberts and found it to be too much. Also, the filberts are cooked in the sauce, if you follow the recipe. I recommend using them as a garnish, because they turned a VERY unappetizing purple in the sauce.

I would also recommend increasing the amount of brown sugar by 50%.

With those changes, I think you will find this to be an excellent recipe.