These are designs taken directly from Raspberry Pi's archive here: https://datasheets.raspberrypi.com/rp2350/Minimal-KiCAD.zip
Unpacked so they can be viewed with KiCanvas.
You can read more about Hardware Design with the RP2350 here: https://datasheets.raspberrypi.com/rp2350/hardware-design-with-rp2350.pdf
Convenient KiCanvas links:
All rights to these designs belong to Raspberry Pi, I just unpacked them and put them on GitHub.