The most common and most likely answer to this crossword clue is the 5 letter word BUXOM
I've seen this crossword clue in The Times
B
U
X
O
M
More clues leading to the result BUXOM
Buddy explains!

The straight part
We know that "Pleasingly plump" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case pleasingly plump = buxom.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does BUXOM mean?
BUXOM adjective- Pliant, obedient, tractable (to) (i.e. easily moved or bent, morally).
- Submissive, humble, meek (as subsense of 4).
- Gracious, indulgent, favourable; obliging, amiable, courteous, affable, kindly (as subsense of 1).
- With infinitive: Easily moved, prone, ready (as subsense of 1).
- Flexible, pliant (arising from sense 1).
- Blithe, gladsome, bright, lively, gay (attested after 1).
- (of a man or woman) Cheerful, happy (possibly as subsense of 6).
- (chiefly of women) Full of health, vigour, and good temper; well-favoured, plump and comely, 'jolly', comfortable-looking (in person). (arising from sense 6).
- (of a woman) Having a full, voluptuous figure, especially possessing large breasts (as subsense of 8).