I made a all maple cutting board and a thin walnut endgrain cutting board.  It was only 5/8" thick.

I used spray adhesive to affix the font I chose to the walnut.  I cut it out with a band saw.

I set the W on the maple board and traced around it with a pencil.  I then used a up spiral router bit to take passes getting progressively deeper until I hit 1/2" deep.  I also used a 1/8" router bit to get into tighter spots.  Then I chiseled to my lines.  

Then I squished the W into the hole using a piston clamp and a board with waxed paper on it.  The epoxy spewed out.  I then used a belt sander to wast away the 1/8".  The fit was not perfect, but the epoxy filled the gaps ok.