While this looks like a regular cake, there is something very special about it. It was the first time I made the American buttercream in a similar way as the meringue buttercreams, minus the cooking. I'll just let Wicked Good Kitchen explain it, since that's where I got the technique.
This technique made the buttercream really smooth and it has such a beautiful mouth feel, and doesn't taste too sweet either. It was a little more loose than I'd like, but as you can see in the video below, it still holds its shape really well. and like the title of that blog says, it definitely is for me, the "Best Ever American Buttercream"