How much Hashish for Brownies?

• tl;dr how much (over 26% THC containing Hashish) for first time edibles (brownies) in cannabutter

Hello there!

I smoke weed for half a year now and nearly monthly. I wanted to make some edibles(brownies) since one of my friends does not want to smoke it and we dont have a vaporiser(it will be his first time trying weed). The guy i got it from says it contains over 26% THC (I bought Hash insted of cuttings, bcs a friend told me to do so, i think i should have bought cuttings tho). How much Hashish should we use per person(we are 4) if we make cannabutter and then brownies?

Do you have any tips on how to make the brownies/cannabutter? Yes, i know that i have to use water and wait for a long time :D