Step 1

Heat oven to 350ºF.

Step 2

Whisk eggs, sour cream and 1/2 tsp. vanilla until blended. Set aside. Combine flour and baking soda in large bowl.

Step 3

Cook stout and 1 cup butter in large saucepan 2 to 3 min. or until butter is melted and mixture is well blended, stirring frequently. Remove from heat. Add granulated sugar and cocoa powder; mix well. Stir in egg mixture until blended. Add flour mixture; mix well.

Step 4

Pour into 2 greased and floured (9-inch) round pans.

Step 5

Bake 35 to 40 min. or until toothpick inserted in centers comes out clean. Cool 10 min. Remove cake layers from pans to wire racks; cool completely.

Step 6

Meanwhile, bring remaining butter just to boil in saucepan; simmer on medium-low heat 3 min. or until lightly browned. Cool.

Step 7

Beat cream cheese, powdered sugar and remaining vanilla in large bowl with mixer until blended. Gradually blend in butter, being careful to not add sediment from bottom of pan; discard sediment.

Step 8

Stack cake layers, filling layers and frosting top of cake with cream cheese mixture.