I can think of a couple of ways to skin this cat...
handheld router or router table?
what kind of wood? pine? Poplar?
I can see doing this with a tablesaw in fact, Thinking the face is a soft wood, sanding down the profile would be relatively straight forward and quick. Set the blade height and adjust your fence for the first plateau, make your 4 passes, drop the blade, narrow the fence and make your 2nd plateau..then hand sand the profile..
Pretty much the same idea with a router bit...
"..... limited only by imagination"
"Just smile and wave boys, smile and wave"
Skipper the Penguin