By itself, paned just means "a cuppa" -- a cupful of something.
But by convention, "a cuppa" in most of the UK is specifically a cupful of tea, rather than a cupful of coffee or creosote or jelly beans.
A bit like somebody who goes outside "for a smoke" will usually be smoking tobacco (most often a cigarette), not marijuana or oregano or dried buffalo dung.
I laugh every time I read your response, mizinamo! Dw i'n chwerthin heddiw!
Earlier in this lesson duo told me that 'cuppa' was 'disgled' or something. Is there different dialect names for a cuppa in Welsh?
I believe disgled is more a northern term.
Edit: paned and disgled are different dialect terms for the same thing (a "cuppa", i.e. a cupful of something, typically tea), with paned (or with regional pronunciation panad) being more common in the north and disgled more associated with the south.