i don't make cannabutter, but I do make the oil, for when I do the brownies or cakes, the .88 cent betty crocker ones, i made sum yesterday
......
drop about 1/8th or 1/4 of bud (if it's good bud you dn't need too much, the slow simmer will extract as much THC and cannabinoids from the bud as smoking it) nice and broken down in a grinder into a saucepan, with 1/3 r 1/4 of oil and simmer on low for 3-4 hours stirring every 10 - 15 mins... it's gotta be on low... it can "fry" but i prefer it's just a tad cooler....
now you can strain it, using a wire strainer like this one:
http://www.walmart.com/catalog/product.do?product_id=11926774
i personally leave the plant matter in there, if it's real broken down, with no stems, after 4 hours in the oil the plant matter will be so crispy that I can't even tell it's in the brownies when eating them... i then make the brownies according to the recepie on the box.... i make brownies all the time, it's awesome, and simmering the buds in oil for a couple of hours is the way to do it, i've done it since the first time i made brownies about 5 years ago, and still use the same method and still get high as fuck every time.....
enjoy!!!