  The PANCAKE facility is the world's largest liquid xenon test platform.
Inside its cryostat with an internal diameter of 2.75 m, components for the
next generation of liquid xenon experiments, such as DARWIN or XLZD, will be
tested at their full scale. This is essential to ensure their successful
operation. This work describes the facility, including its cryostat, cooling
systems, xenon handling infrastructure, and its monitoring and instrumentation.
The inner vessel has a flat floor, which allows the full diameter to be used
with a modest amount of xenon. This is a novel approach for such a large
cryostat and is of interest for future large-scale experiments, where a
standard torispherical head would require tonnes of additional xenon. Our
current xenon inventory of 400 kg allows a liquid depth of about 2 cm in the
inner cryostat vessel. We also describe the commissioning of the facility,
which is now ready for component testing.
