No founder, sponsor or establishing record for National Brownie Day has been located. The phrase turns up in only two volumes in HathiTrust's full-text index, consecutive 2007 and 2008 issues of one trade serial, so the day is recent in print however old the recipe under it is.
The first Brownies were not brownies
Farmer's 1896 first edition files Brownies in the cake chapter, sitting between Cup Cake and Ribbon Cake. The ingredients are butter, powdered sugar, Porto Rico molasses, an egg, bread flour and pecans, and the instruction is to bake them in small shallow fancy cake tins and garnish each one with half a pecan. Nothing with chocolate in it turns up under that name anywhere else in the book.


