This is a remix that I scaled up to fit on the Ender 3 S1 Plus. The Oreo shelf prints in 3 separate pieces that will need to be combined with an adhesive. I used some E6000 I had lying around, and it turned out great! I also included a separate cream filling stl if you want to go a different route with mounting.

The wall mount bracket is very simple and attaches to the wall via two screw holes, and then the shelf just slides over it. I printed mine out of some basic PLA, though you may want to consider a sturdier material if you're planning to put anything weighty on the shelf. This setup works for my purposes, though.

Check out my girlfriend's video to see it in action! https://www.tiktok.com/@floral.katiee/video/7272817582779026734?is_from_webapp=1&sender_device=pc&web_id=7274233283252913710