Another favorite of mine is hillbilly peanut butter fudge - nuke one container of storebought vanilla cake frosting with one jar of creamy peanut butter until it all melts, stir, refrigerate. Frickin' delicious. And about the most fattening stuff in the universe.
That's a nugget from the quarantine goldmine. Do you stir until there is ribbons or until its thoroughly mixed together? I'm making this soon.
Microwaves vary, but try dumping the tub of frosting and jar of peanut butter together in a bowl, nuke for one minute, stir, nuke another minute, and by that point it should be very creamy. Stir thoroughly and chill, no need to do anything else.
Takes no time at all, is ridiculously rich and good if you have a sweet tooth. Best kept chilled.