From by Emily Lael Aumiller's 2016 cookbook, Pure Artistry:

I am blessed with a backyard at my Brooklyn apartment. Imagine that, in New York of all places! As a gardener, I had been deprived for way too long, so when we moved into the apartment, I went at it. I got a bit slaphappy, and by the end of the summer I had basil coming out of my ears. A girl couldn't make any more pesto, so I started making basil oil (see page 20 for instructions), and then came up with this one-of-a-kind icing.