Chocolate frosting, versions 2 and 3

I made a nice chocolate frosting for my Osterlamm (lamb-shaped German Easter cake) a couple of years back, but didn't write it down and didn't remember it well. This week, I wrote a frosting recipe down, but it didn't work. Here's the failed recipe and the way I fixed it.

Chocolate Frosting, version 2

1 stick unsalted butter
1 package semisweet chocolate chips
about 1/2 cup cocoa powder
2 Tbsp powdered sugar

Melt butter over medium heat. Turn off heat and whisk in small batches of chocolate chips until they melt. Whisk in cocoa and powdered sugar. Cool in separate container.

I should add to these instructions "do not put the bowl of frosting in refrigerator" because when I went to look at it the next morning, I had a large, solid truffle instead.

How to rescue it to frost a cake before taking it to a party later that day? Break the truffle into pieces and whisk in 3/4 cup hot milk (in my case, I used almond milk). This turns the truffle back into something more like fudge sauce. Whisk in a bit more cocoa powder to stiffen it up a little more and cool to room temperature for frosting. The end result is a cake covered in ganache, which is kind of like turning the Osterlamm into the best-tasting chocolate bunny ever.

Once again, if stored in the refrigerator, this will turn solid again (although much softer with the liquid milk in it). It needs to come back to room temp again to be at all spreadable. Warmer than room temp would be easier to frost with. I just ended up putting slightly warmed "version 3" in big globs on chunks of leftover cake yesterday. A chocoholic's dream.

Next time, I'm using cream for a proper ganache frosting, or I'm making chocolate buttercream. None of this fence-sitting butter-ganache, delicious and decadent as it may be.