Are these new Food52 single subject cookbooks compilations of recipes from here on the site? Or are they new recipes dreamed up by the paid staff?

Just like all our Food52 Works books with Ten Speed, Mighty Salads and Ice Cream & Friends are a mix of half greatest hits from the website, and half recipes that are new to the book (though we come up with those newbies in different ways each time—this time we tapped a couple of longtime community talents, cristinasciarra and EmilyC to develop the new recipes and they are SO good.). There's lots of details about how the new books came together in this blog post: https://food52.com/blog/18852-here-come-our-next-two-cookbooks-there-s-ice-cream-involved