You might be able to do a triple drabble. You almost made it on the one that you said was 340 words. You could challenge yourself to write 300 words. :-)

I joined sereral drabble communities, because it's a fun challenge to have to either write exactly 100 or 200 words. I've had a couple of funny moments when I've lost control and suddenly have to just let the drabble go and en up with a longer fic, because I'm way over the word count. :D