Thanks Thimblebug. You know what's aggravating - I was just at Missouri Quilt Co a couple of weeks ago! Matter of fact - that's where I bought several layer cakes! LOL - Murphy's law. I wish I had know about that template then.
I played around with some scraps and it looks like if I cut a 45 degree diagonal line starting at 4 3/4" on on one side and ending at 6 1/4" on the other side it works out. Now to figure which ruler would be best to use and mark it with painter's tape. I'm thinking a 6 1/4" square for the center. My math is not the greatest so that will be trial and error too. Oh well!