I wanted to do this for the employees (my husband is one). They work so hard and I just wanted to do something nice for them. Center is 10" square white cake and corners are chocolate 10" circle cut and trimmed to match up. All buttercream and a fbct for the center. For some reason, the left side did not want to adhere to the cake....ugh! So, I had to try and redo it. But this is what I ended up with. Many thanks to blissful for your insight!