The Wallykazam! reference means that the title, The Cake Monster, sounds similar to Cookie Monster. Watch The Thundermans episode "Cookie Mistake" and the "Cookie Thief" quote sounds like the Sesame Street episode. I re-undone everything undid to me except for The Loud House ref because it was similar to Eight Take-Away One Equals Panic but wasn't a mention.
We don't count the use of the phrases "cake monster" (which is an episode title). I checked the Thundermans episode (a sped-up version, around the fifteen minute mark) and she says "cookie thieves" (plural) to characters she thinks are stealing a cookie. That's not a reference either.
If you want to add to Muppet Mentions pages, I'd suggest focusing on either uses of actual character names (not something similar) or unmistakable parodies (where something is clearly based on Sesame Street or The Muppet Show, not because you think it looks or sounds similar, unless there's a quote from someone involved to say it's intentional). If you're not sure, feel free to ask here in the forums before adding.