I think most would use a pop up receptacle:
That’s correct. Face up receptacles are prohibited from being installed in a countertop.
Is there any requirement for those pop-up gadgets to be “spill proof” when recessed? I think most people would rather have those instead of side-mounted receptacles anyway, but my concern would be spilled liquids running in and messing up the workings.
The receptacle needs to be listed for use in work surfaces or countertops. There is no NEC specific requirement for it to be spill proof however that is likely part of the listing of the device.
2023 NEC:
210.52(C)(3)3. In a work surface using receptacle outlet assemblies listed for use in work surfaces or listed for use in countertops.
406.5(G) Receptacle Orientation
(1) Countertop and Work Surfaces
Receptacles shall not be installed in a face-up position in or on countertop surfaces or work
surfaces unless listed for countertop or work surface applications.
Counter (Countertop). A fixed or stationary surface typically intended for food preparation and
serving, personal lavation, or laundering or a similar surface that presents a routine risk of
spillage of larger quantities of liquids upon outlets mounted directly on or in the surface.
(CMP—2)
Informational Note No. 1: See UL 498, Receptacles and Attachment Plugs, and UL 943,
Ground-Fault Circuit Interrupters, which establish the performance evaluation criteria and
construction criteria.
Informational Note No. 2: See 406.5(E), 406.5(G)(1), and 406.5(H) for information on
receptacles for counters and countertops distinguished from receptacles for work surfaces.
Part of the listing requirements for popup receptacles are its spill resistance characteristics. Countertop are 128 ounces while work surface is reduced to 64 ounces.