Yup that's what I do with mine. I just dump them in any brownie batch I make. I've never just made a batch of brownies with only vapped weed, but I'm sure it would come out fine.

I think about it in these terms if your use 40 grams of vapped weed and you extract the last remaining 5% to 10% of the THC and other chemicals in the weed then it's like you put and extra 2 to 4 grams of weed in your brownies. Most definitely vaped weed is full of unused THC.