This will make a 3D model that is like a "cube" made with two letters. From one point of view, let's say the front view, one letter will be seen. From the right view another letter will be seen. I did it for the first time using Blender, but wanted to make a customizable model, as I started to print it as a gift for people who came to my house and got interested by the 3D printer.

Code obtained at https://www.thingiverse.com/thing:3004457 to measure the letters size.

The "Customizer" only works with one big file, so I've created an additional file for it called initials_cube-customizer2.scad. If you download files for rendering locally, use the other 3 *.scad files and render initials_cube.scad changing first variables on the file.