This amazing book by 16th century chef Bartolomeo Scappi (1500 - 1577) has some of the earliest mentions of pizza in history! There are a few pizza recipes, none of which resemble what we think of as pizza today. Scappi was big-time, having served in the kitchen for several popes during his career.
One recipe uses the word pizze to describe a “flaky-pastry for a day in Lent.”
"Get two pounds of flour, warmed milk made from either six ounces of Milanese almonds or else one pound of shelled pinenuts, three ounces of sugar, two ounces of rosewater, one ounce of salt and two ounces of sweet-almond oil; mix all that together with the flour and make up a dough of it that is not too firm. Knead it well for a quarter of an hour, and make a long, thin sheet of it. Brush it with sweet-almond oil or olive oil, sprinkle it with sugar and cinnamon, and roll it up like a wafer cornet. When the twist is made, make tiny wheels of it and make pizze of those wheels by spreading them out with the heel of your hand. Those pizza can be baked in a pan like tourtes, or else you can fry them in oil. Serve them hot with sugar over them.”
This recipe defines pizza as a dessert dish that has absolutely none of the ingredients we think of today. No mozzarella (too expensive), no tomato (it wasn’t brought from the New World yet) and certainly no pepperoni (that isn’t even Italian). We think of pizza as a peasant dish, but here we have the pope’s chef making it, not to mention he’s in Rome and not Napoli. The word seems to have changed meaning over the years, eventually becoming the modern version two centuries after this book was published in 1570.