it's called Texas Sheet cake or Chocolate Buttermilk cake. But whatever you call it, it's so delicious. I made a pan on Saturday for a funeral lunch. Dave saw it sitting on the counter and asked, "Why don't you ever make this for us any more?" And I had not made it for a very long time (we're talking years). So, while he was gone later that day I made up another pan just for us. I bake mine in a 9x13 pan instead of a large cookie sheet so it comes out super thick. So this week I've had a piece every day...okay, maybe some days I've had 2 pieces. It's the best when it's heated up in the microwave for 18 seconds and the frosting is starting to melt and the cake is warm. Lucky for me it's gone now. I'll have to make it again in a few months....long enough to forget about it so when I do eat it again it's SO GOOD. I don't know what it is about a warm, dense, chocolaty cake that just makes the day feel a little better. I love this cake. I just really, really love it.