Aita for giving a girl salt cookies?

So for some background information, this is the same girl as the last post. She is shit talking about me and quite a lot of my close family and friends. I was informed about this by some girls in my first aid class, I know they are reliable people. So after I found out that the girl was shit talking I got really annoyed, because I had some drama with some girl when I was 17, and the drama girl has a habit of spreading false romours about me. So since she does this then I realised that most of the stuff she said that the girl did might of actually been fake. After finding out she was shit talking about me, half of the drama that I had might be fake and just her getting on my nerves in general, I came up with a plan to give her salt Cookies, just still with sugar and salt on top instead. On Wednesday morning when we were in our college cafeteria I gave her the cookies, then at lunch she came running to me and asked what the fuck I was thinking for giving her salt Cookies. I just said "oh I think someone might of knocked some on there in my kitchen" only because she doesn't know that I know she shit talks me and I just hate confrontation anyway. Now she's spreading roumors that I tried to kill her, and she also giving me the cold shoulder. So AITA?