If anybody has more information, let me know and I will update the post. Took a while researching. Closest I came was this article https://www.cnbc.com/2017/10/13/where-did-national-dessert-day-come-from.html which links to National Today website below.
I saw #NationalDessertDay trending on Twitter. I checked Wikipedia and sure enough, today is National Dessert Day – https://en.wikipedia.org/wiki/List_of_food_days. Not seeing a whole lot about the day –https://nationaltoday.com/national-dessert-day/. Seems to be a mystery so far. Went here and got not very much – http://www.holidayscalendar.com/event/national-dessert-day/.