*If you love a strong hazelnut flavor, I strongly recommend you use Nocciolata brand. It has a great thick, creamy, chocolate, hazelnut flavor that really comes through in these cookies. Also, I used the entire jar (9.5 oz.), which resulted in 3/4 cup of hazelnut spread.
**The original recipe called for 1 egg, so feel free to substitute 1 egg for the 2 egg yolks. I happened to have 2 egg yolks left over from another recipe, so I used them in these cookies. The reason I published the recipe with the 2 egg yolks in the ingredients list is because that's how I made it, and I wanted to be sure I represented it exactly as I made it, so I could accurately represent the flavor profile to my readers!