Drip cakes- Whats the drip?

In order to "drip" a topping over buttercream, that buttercream should be very cold - frozen is best, and the topping can't be terribly hot. All chocolate, and all buttercream, is different, so I suggest doing a test, and having an offset spatula near by to remove what you don't like, to start over if you wish.

So I found this. http://www.delish.com/kitchen-tools/a42545/drip-cakes-katherine-sabbath/
Like I said I've only done chocolate ganache. She says to wait 10 minutes to allow it to cool a little; I don't think wait quite that long with chocolate, but maybe it's different with white chocolate. I do use that method of coaxing over the edge with a spoon or spatula though.

Since the sixties, my mom has been making an angel food cake frosted with cocoa flavored whipped cream and drizzled with a delicious chocolate ganache. The kind made with whipping cream that doesn't harden. It was always my favorite birthday cake preceded by marinated flank steak cooked over an open flame in the fire pit in front of our Mission Beach house. Good memory.

I've done this for years with chocolate glaze over a bare hazelnut torte, without the frosting underneath. It's a simple glaze of dark chocolate melted with a little olive oil (or butter) and a little orange juice.