Texas sheet cake

Was it your New Year's resolution to come up with more recipes that incorporate Dr. Pepper and 4 sticks of butter?  I mean who's wasn't?!  If so then I have the cake for you!  If not please immediately avert your eyes.
 I had no intentions of starting the year off with such extreme calorie overload but was left with no choice.  It happened on a Tuesday when I received the Wheaton magazine.  I was casually flipping through the pages when a lovely smiling face looked up at me.  Oh, she's cute I thought.  And then I read that this girl, I think her name is Jennifer, graduated from Wheaton and went on to become a highly respected chef in Chicago.  She was actually voted best pastry chef of the year in 2011.  On top of all that she worked at Charlie Trotter's (the now closed but highest rated restaurant in the city) and now works for Rick Bayless at Topolobombo.  If your not a foodie this means nothing to you but basically she served this recipe at her staff parties for famous chefs.  I was so intrigued by the recipe I had to give it a try.  I can't even imagine how it came about or how her day looked in the kitchen when she dreamed this up.  Let's see, "what this recipe needs is more marshmallows and some Dr. Pepper."  Anyway, long story short....if you want to gain five pounds this week let's get cooking.

Lightly butter and flour a standard haf sheet pan (she says a 9x13 would work too)

Then set aside 1 cup of Dr. Pepper 

Grab a saucepan (mine was too small) and melt

2 sticks of unsalted butter

4oz. of marshmallows (15 big marshmallows)

3T of cocoa powder (I used Ghiradelli's)

1cup of Dr. Pepper

While that is melting over medium heat sift together:

2 cups all purpose flour

1tsp baking soda

2 cups sugar

just mix gently with a rubber spatula

In another bowl whisk

2 eggs

1 1/2 cups buttermilk

1 tsp vanilla

The first mixture is almost melted....

Perfect

Pour the above mixture over the dry ingredients

And then fold in the egg mixture gently until it's just combined

Pour the mixture into the pan and bake at 350 for about 19 minutes (I probably did mine 21 minutes) until the cake springs back in the center when touched. Let it cool.

At this point I started drooling a little and forgot to take any pictures of the rest of the process.  Which is unfortunate because here's where the recipe goes from crazy to ridicudonculous.
For the icing:
Comine in a saucepan:
2 sticks of unsalted butter (now it's a party!)
6 T Dr. Pepper
3 T cocoa powder
1 tsp. vanilla
Heat on medium until barely simmering.  Take off the stove and whisk in
1 pound of powdered sugar. (no she ding dong didn't!)
Whisk to dissolve then stir in
1cup chopped pecans toasted until fragrant (about 5-8 minutes at 350) (see it's healthy!)
You want the icing to be warm when you pour it over the cake because it sets really fast.  I also forgot to take any pictures of the finished product but here are the five remaining on my counter and they're still yummy.  It's got a really unique flavor and texture.  The cake is fluffy but it tastes a lot like fudge.  It would be great for a crowd.  I've served it as dessert for three separate dinners to rave reviews.  Enjoy and I'm sorry!