What would happen if you forgot to use flour when baking?

One time I was making sugar cookies and I accidentally used powdered sugar instead of flour (they look kind of similar, right? haha). The cookies basically melted into a giant blob that leaked over the sides of sheet. Not a fun mess to clean up. And not even my dog would eat the sugary goop I created.

I just did an experiment on what would happen if i didn't add flour to the chocolate chip bars i made. when i took them out of the oven it was black soupy and bubbling!! it looked like tar and it was a MESS to clean! If you dont add flour it wont rise