I have never tried to make panelles but have eaten them on the streets of Palermo.
Here is my recipe for pignoli cookies which I got from that great website epicurious.com. I had been looking for a good recipe for years for my Sicilian-American husband. (His Sicilian grandma made them - and so did all the Italian bakeries in the Bronx of his childhood.)
2 8-ounce CANS of Solo brand almond paste (not marzipan, not almond filling, and don't use the tube paste!)
1 1/2 cups of confectioners sugar
1/2 tsp. salt
2 large egg whites
2 tbls. honey (optional)*
1 cup of pine nuts (pignolis)
Preheat oven to 350. Machine mix almond paste until broken up (it will never break up completely). Add sugar, salt and continue to mix for about one minute. Beat together almond mixture, egg whites and honey until as smooth as it can get (it won't get that smooth!) Spoon drop mixture in about 1 1/2 inch rounds onto parchment paper-lined cookie trays. Press several nuts onto tops of each cookie. Bake until golden, about 12 to 15 minutes.
*I've never used the honey and the cookies are still celestial.
Thanks.
I worked as a pastry man for eight years and I must have approximately a dozen of those cookies.
Haven't worked in a bakery in about 25 years, though.
Without changing the receipe you gave I would make the following changes:
Lay out the pine nuts on a flat dish or a tray and spoon drop them on the nuts.
To be able to spoon drop the mixture tells me the mixture is too soft. So delete the honey. Actually in all the receipes I have, very little honey was used. Honey is usually added to hasten the browing process. Instead of honey we used a cookie softner called Nulomoline.
Bake them at between 400-425. I'm guessing here in your original recipe the cookies come out too flat and too dry, similar to amaretti. The low temperature allow the mixture to spread out more than usual before it takes a crusty shape.
But, if it works for you, please don't change a thing. :)