Most bananas in pastries kept in sack (8)

I believe the answer is:

loopiest

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'most bananas in pastries kept in sack' is the definition.
I can't judge whether this definition defines the answer.

'pastries kept in sack' is the wordplay.
'pastries' becomes 'pies' (pie is a kind of pastry).
'kept in' is an insertion indicator.
'sack' becomes 'loot' (I've seen this before).
'pies' going into 'loot' is 'LOOPIEST'.

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I've seen this clue in The Guardian.

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