Nothing fancy here - these are meant to work!
I had a nice hunk of 8/4 red oak left over from my queen size platform bed project and had thought for months about using it for an end grain cutting board. This is the result.
The large board is about 15.75" by 12.25"; small one is 7" square. I had intended to make just the large board and made up a couple of extra strips in case I had an issue with any others. All of them worked out fine, so I decided to make a little sister for the big board.
The board I started with was about 1.875" thick by almost 10" wide. By the time I milled it up, I had strips a hair larger than 1.75" square by 14" long. The wood remained stable throughout the processes because it was a quartersawn piece to start with and had been in my shop for a couple of years. I wanted something other than square corners and played with some options in SU. I printed a template and shaped a scrap of 1/4" plywood to use as a pattern to mark the corners. After bandsawing and disc sanding, I had the shape I wanted. A 1/4" roundover on the top and bottom edges finished both boards. The next step was to apply several coats of mineral oil.