Is there such thing as chocolate beer?

I'm sure. That question came from my brother, who turned 20 today. We gathered for birthday celebration and, without a clue of what to buy him for his special day, I made a cake. So I don't know if there's really a "chocolate beer" (there must be), but there is a beer-chocolate... in this cake.
Of course, Austin's birthday is the same day as St. Patrick's Day, so I could've just done Guinness cake, which I've done before, as cupcakes. I almost even ran out of the house last night to buy Guinness. I'm not sure if my reason for not doing so was to not seem like a teenager tryin to get my hands on some Irish Car Bombs, or because I found this other great Brooklyn Brown Ale in my fridge and therefore didn't have to leave. Either way, I made Brown Beer Chocolate cake, topped it off with cream cheese frosting (homemade, of course), and served it for dessert, after a too-filling Mexican feast.
I'll have to try it again tomorrow when my stomach doesn't feel like it's about to explode, but as far as I can tell, all family members (who I can only assume were as full as me) ate a piece, and gave good feedback (isn't a clean plate enough?).

You can actually taste the chocolate and the ale, and it's quite nice, subtle, complex.
Here you go. I made it in a springform pan, and only frosted the top. Simple. Good. (Usually I find myself partial to the 2-layer cake, filling and covered in luscious frosting; this time, I settled for frosted top only, and I'm glad.) I will say that the middle seemed it was about to implode. It never did, but it did sink mildly. You couldn't tell, though, with the thick frosting on top.

Brown Beer Cake
3/4 c cocoa
9 T butter
2 c sugar
2 eggs
1 c dark brown ale (such as Brooklyn Brown Ale)
3/4 c sour cream
1/2 c whole wheat flour
1 1/2 c all-purpose flour
2 1/2 t baking soda
1 t salt

In a medium saucepan over medium heat, melt butter. Whisk in cocoa and sugar. Pour into medium-large mixing bowl. Add eggs, beat well. Add beer and sour cream. Stir well. Separately mix dry ingredients, then add them to the mix. Whisk. Consistency should be thick but still liquidy, pourable.
Lightly oil a round springform pan and line bottom with parchment paper. You can dust with cocoa, too, if you want, but no pressure. I didn't. Pour in cake batter. Bake at 350 for 45 minutes, exactly, or until a wooden skewer/toothpick inserted comes out practically clean.
Cool on rack. When TOTALLY COOL (next day is good, too), frost with your best cream cheese frosting (mine is: 1/4 c butter+1/4 c cream cheese+1-2 c confec. sugar, depending on your taste, beaten). Enjoy!