International Pizza Cake Day is celebrated annually on the third Thursday in April, with April 16 being the date for this year. The day encourages people to have fun with pizza cake, which can be either a cake that looks like a pizza or a pizza shaped like a cake. It originated from a promotion by Boston Pizza, a Canadian-based pizza chain, which introduced the pizza cake concept in 2014. The pizza cake is typically a six-layered creation, with some claiming it contains around 5,000 calories. Celebrations may involve making a pizza cake from scratch or stacking pizza boxes to form a cake. The day is an opportunity for pizza lovers to enjoy this unique dish in various forms.