I trialled this recipe alongside another from Scappi (II.180) and one from Castelvetro, so these are what the comparison is to.
Scappi, Bartolomeo, Scully, Terence (trans.), The Opera of Bartolomeo Scappi (1570): L'arte et prudenza d'un maestro cuoco(Toronto, University of Toronto Press, 2008)
It seemed a bit much to be first frying the spinach in butter and then boiling it also, but I nevertheless did both. I used a really large bunch of spinach, chopped it small and fried it with roughly 50 grams of butter. Once it had cooked down, I put it in a pot and boiled it with a selection of herbs - fennel, sage, rosemary, and mint. As Scappi calls for a handful to be added, I added whole sprigs and fished them out once everything was cooked. Normally he would tell you to chop the herbs if this is what he wanted. Reading the recipe again, I wonder if he meant that the spinach should boil in the butter instead of water - it's a bit hard to tell. It would have taken quite a lot more butter to be able to boil the spinach in it, and I am not entirely convinced that even the Pope could handle that much butter clogging his arteries in one dish.
After the spinach was cooked I added about 1/3 of a cup each of Parmesan and block edam cheese. Scappi just calls for a "creamy" cheese in addition to the Parmesan, so it is hard to tell whether he wants a soft or a hard cheese as he also considers Parmesan to be creamy. Spice-wise I added in a decent 1/2 teaspoon each of pepper and cinnamon, along with a pinch of cloves and a generous pinch of saffron; I also added a handful of raisins. I only added one egg, but this seemed to be plenty to bind the mixture. Scappi mentions that if the mixture is too moist then grated bread can be added, however, it seemed to be of a nice consistency midway between the two bean recipes in overall texture.
I used the same dough as I had for the other two recipes, although again I should have used the recipe I mention in Scappi's bean tortellini above. Although Scappi says to make the tortellini "of various sizes", I made mine all of the same size - ever so slightly larger than commercial tortellini. Again I cooked them in vegetable broth so that the vegetarians could eat them too.
After much umming and ahhing, most people decided that this was either their preferred option, or that it would be the one to best compliment the lamb which it will be served with. This recipe certainly had the most going on in terms of complex flavours and textural interest, so I can see why it won the day.