I read this book probably in the early 1970s. This is what I remember: a boy lives in an apartment building, something’s weird with one of the neighbors, there’s a brownie that he eats, just a few bites at a time, I think, he notices strange things happening to him, and ultimately, he eats enough brownie and turns into a cat and sneaks into the neighbor’s apartment through an open window ledge.
This might be Ruth Chew’s No Such Thing as a Witch. That had fudge rather than brownies, but it came out in 1971.
No Such Thing as a Witch?
https://www.goodreads.com/book/show/357840.No_Such_Thing_as_a_Witch
That’s it!! No Such Thing as a Witch! Thank you once again for solving the mystery of the forgotten book 😉
Hooray! I read so many of Ruth Chew’s books as a kid and have been thinking about them for years. No author or titles to go on, just remembered the 70s-ish illustrations and that they were innocent magical stories about two children who discover fantasy in ordinary urban places like a park and an apartment building. Spent many long hours (unsuccessfully) hunting for this – thank you!