FEZ Game Number and Letter Cubes, one piece prints.

thingiverse

Remix from DStephenson's model, and all credit to them, if your printer is more capable of bridging than it is printing snap-together parts this might be an option for you. Photo shows both cubes with the bottom surface on the top, so this is about the worst quality side to expect if your printer is fairly well dialed in. I did shrink the relative size of the insets compared to the overall cube dimensions by like .95/1 to avoid gaps at lower print sizes. I printed them at 65% actual model size, .15mm resolution, sanded with 80 then 120 grit (US) sandpaper, dolloped paint into the recesses then wet sanded with 240 wet or dry paper stuck down to a flat surface with water, for a matte finish. use like 4 layer top/bottom/walls if your printer has vertical artifacting and/or issues with the top layer, otherwise 3 will likely work if you're well dialed in. Resin print _might_ work better if you have one of those, angled similarly to the anycubic test cube where everything is at a 45% angle. As always, if you're curious how I remixed this or want to improve more upon it, I've included the .blend file.