I have seen round yellow cakes, so it may be an unusual type that you have let get past prime. But realistically they look more like little squash.. What is the chance they may be volunteers from last year’s fall decorations or from compost?

Looks like lemon cucumber to me too.

And lemon cucumbers left too long on the vine ...as these are .....two tone with orangish stripes...will be bitter probably...they should be harvested when they are pale yellow..and still fairly round...once you try these you may never want the long green ones again...

Totally lemon cuc. I like these!

Thank you all!!!! Will my green cukes come back?

I have small yellow ones. Should I peel them?

Either way good

If you slice into rounds no need to peel