The title is a delightful Britishism PG stumbled upon earlier today while reading an article he deemed too obscure for even him to post (even for him to post?).
From The Phrase Finder:
To ‘over-egg the pudding’ is to go too far in exaggerating or embellishing something – to adorn or supply to excess.
. . . .
‘Over-egg the pudding’ is an English phrase and first appeared in the mid-19th century. It originated as a simple literal phrase alluding to the way that baked foods may be spoiled by using too many eggs.
The earliest examples of the phrase in print that I know of are from 1845 Robert Smith Surtees’ novel Hillingdon Hall, 1845:
‘We mustn’t over-egg the pudding,’ as the Yorkshire farmers say.
Francis Kildale Robinson’s A glossary of words used in the neighbourhood of Whitby, 1876:
He ower-egg’d his market.
As the first of these refers to ‘over-egg the pudding’ as a Yorkshire expression and the second relates to the Yorkshire coastal town of Whitby, it’s reasonable to surmise that the pudding in question is a Yorkshire Pudding.
Link to the rest at The Phrase Finder
And regarding A glossary of words used in the neighbourhood of Whitby, from Google Books:
Link to the rest at Google Books