Chubby

The one where the big dog thought his little kitten friend got baked into a cookie?

That sounds like it might be it, actually! I couldn't remember anything about it except that the cookie looked like that (and that there was something unpleasant going on for one of the characters) until you said that just now. Now I can actually kind of remember the dog like freaking out and stuff watching what he thinks is the kitten being turned into a cookie

So, apparently it's from Looney Tunes, and it's called "Feed the Kitty."
The dog's name is Marc Anthony and the Kitten is pussyfoot.
https://www.dailymotion.com/video/xjw9ms