I think cos you've copied and paste the recipe and directions from that website cheetah identified but you haven't referenced it, so this could be seen as plagiarism. (Although I'm sure this wasn't your intention.)
I think you just put a reference in your post to the recipe you should be fine. You clearly made the cake and have your own photos, it's just not your original recipe (unless that is your website, but you should still reference it).
Looks yum by the way. I wish I had a piece right now.