You can also use one of these, and they don’t look like a poop. (Sorry they only seem to be sold at Walmart and eBay currently, it’s a really good cast iron brand, I don’t know why).
As noted in the YT comments, you can also set your brownie pan in a larger pan of water to nagate the hot-metal effect. Might not be quite as precise, but way easier.
You can also use one of these, and they don’t look like a poop. (Sorry they only seem to be sold at Walmart and eBay currently, it’s a really good cast iron brand, I don’t know why).
https://www.walmart.com/ip/Cook-s-Essentials-Cast-Iron-Elite-Non-Stick-Brownie-Muffin-Pan-with-Spatula-Gold/5398022439
I like this design, although I’m not sure if it’s cast iron.
And for those monsters who want zero corner pieces, you can always make one of these
https://www.youtube.com/watch?v=dXIkUkwzTQU
As noted in the YT comments, you can also set your brownie pan in a larger pan of water to nagate the hot-metal effect. Might not be quite as precise, but way easier.