(The International Dictionary of Desserts, Pastries and Confections, Carole Bloom [Hearst Books:New York ] 1995 (p. 210)
I don't really see a resemblance between these cookies and the palm trees. Do you? Sometimes things get their names from how we would describe them. So these sweet and flaky cookies are also called Elephant Ears, Butterfly Pastries or Angel Wings, etc.
You can make your own puff pastry to make this or if you're like me,
I like to make my life easier so I just use the store-bought Puff Pastry.
Here's a link where I adapted my recipe from: