Pancakes bowled learner over in one (5)
I believe the answer is:
blini
'pancakes' is the definition.
(I've seen this before)
'bowled learner over in one' is the wordplay.
'bowled' becomes 'b' (cricket abbreviation).
'learner' becomes 'l' (as in a learner driver with L-plates on their car).
'over' says to put letters next to each other.
'one' becomes 'i' (Roman numeral).
'b'+'l'+'in'+'i'='BLINI'
(Other definitions for blini that I've seen before include "Eastern European twenty four Ac" , "Russian pancakes" , "Straw hat" , "Russian pancake served with caviar and sour cream" , "Buckwheat pancakes" .)