Heat speeds up the process of dissolving the THC into whatever you are using, alcohol or oil. So heat is not required, but it speeds up the process. So if you are using alcohol, you can let is sit at room temp, and then depending on who you ask, people say it takes days, weeks or months to dissolve it all. Or you can use a double boiler like I have done and make it in less than an hour. I assume the same is true for oil --- heating the oil in a crock pot or other method will get the job done quickly. But maybe you can let it sit at room temp for long enough to extract as well --- I guess you'll find out. Please post back and let us know how it works.

Also, the heat does activate certain non-psychoactive compounds to become active THC. As you mentioned, you will be cooking the brownies, so maybe that activation process will occur during the baking. Let us know.