Is there a synonym for "centerfold" which doesn't also mean "scantily clad woman?"

Centre spread is commonly used in publishing the the two-pages that belong to the same piece of paper and face each other.

Centre spread:

The two pages opposite each other in the middle of a newspaper or magazine, which usually deal only with one particular subject and include many pictures.

Example: Tomorrow's edition will include a centre spread on the Spanish royal family.

[Cambridge English Dictionary]

Or double-spread.

Double-spread:

An advertisement that covers two facing pages (as in a newspaper) — called also double-page spread.

[Merriam-Webster]

Double truck: Double truck refers to a pair of facing pages, usually in a newspaper or magazine, with content that stretches over both pages.

In most newspapers and magazines, the booklet-like format is accomplished by folding large sheets of paper in half. This allows the pages to be opened like a book. Sometimes, usually only in magazines, the pages are stapled or stitched at the fold to hold the pages together.

[Wikipedia]

See Also

Double truck: a 2-page editorial or advertising layout (as in a newspaper) made up as a single unit

[Merriam-Webster]