I like to mix the pot with the penut butter. You get this greenish/brown looking gunk but it puts more weed in contact with the pb (i.e fat). I've never used the microwave so I won't comment but 15-20 minutes in a oven wrapped in aluminum (al-u-mi-nium) foil is all you need. You MUST wrap them in the foil or they WILL burn.

P.S Use as much pot as you think you need. Consider it takes 3-10x the amount to get high when eaten.