Is there a way to set up a shortcut so that I can rotate an object 90 degrees with one button?

I’m making a boomershooter and to facilitate level design, I made square modular pieces that snap together. Right now, I’m having to hit R, Z, 90 or 180, or -90 and it’d be three to four times faster if I could hit a single key.

I’m playing openRCT2 right now and it’s nice just hitting one key to rotate things in that. I wish I had that for building my levels in Blender.