Baffling question (5)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">baffling question</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for poser that I've seen before include "Show-off" , "Tricky clue" , "Puzzling problem" , "Tricky problem" , "What's difficult" .)