My son had this marvelous round cake on his first birthday at Pretend City. Now let me tell you, this cake was HUGE. It was meant to serve 40, but it could have honestly served at least 60.
When the gals went to cut it I was surprised to see them stick the knife near the center of the cake and instead of going down to the edge of the cake, they continued to cut it in a circular form.
Until it looked like a cake within a cake. Then they just sliced from the rim of the "inside" cake outward.
As it turns out, cutting a round cake this way makes it way easier to serve the pieces! Each piece was the same size, it didn't break when it was served and the leftover cake (which for us was the "middle") was easy to take home because it was basically just a smaller cake!
Live and learn! It was such a great tip and I know I'll be using it from here on.