Chocolate Guinness Cake

1 cup stout or porter beer
10 tablespoons unsalted butter
3/4 cup unsweetened cocoa
1 1/2 cups granulated sugar
1/2 cup brown sugar
3/4 cup sour cream
2 eggs
1 tablespoon vanilla
2 cups all-purpose flour
2 1/2 teaspoons baking soda
1/4 teaspoon salt
Preheat oven to 350 degrees. Grease a 9-inch springform pan and line the bottom with a round of parchment or wax paper and then lightly grease the paper. If making cupcakes, line the pan(s) with paper liners AND lightly spray them with cooking spray.
In a large saucepan, heat the beer and butter over medium-high heat until the butter has melted. Add the cocoa powder and sugars and whisk together. Take off the heat and allow to come to room temperature. (Only takes a few minutes)
In another bowl, whisk together the flour, baking soda and salt. Add to the beer-butter mixture and whisk together until it just comes together. Pour into the prepared pan and give the pan a few short drops onto the counter to remove any air bubbles. If making cupcakes, fill each well three-quarters full with batter.
Bake cake for 50 to 60 minutes, cupcakes for 18 to 20 minutes, or until a wooden pick inserted in the center comes out clean. Allow to cool on a wire rack. Run a knife around the edge to separate the cake from the pan, if necessary, and remove the ring from the springform pan.
Frost as desired. A classic cream cheese or chocolate buttercream frosting is very good.
This recipe makes a LOT of batter and would easily make 30 to 36 cupcakes.