Grease a 9-in. springform pan and line the bottom with parchment paper; set aside.
In a small saucepan, heat beer and butter until butter is melted. Remove from the heat; whisk in sugar and cocoa until blended. Combine the eggs, sour cream and vanilla; whisk into beer mixture. Combine flour and baking soda; whisk into beer mixture until smooth. Pour batter into prepared pan. Bake at 350° for 45-50 minutes or until a toothpick inserted near the center comes out clean. Cool completely in pan on a wire rack. Remove sides of pan. In a large bowl, beat cream cheese until fluffy. Add confectioners’ sugar and cream; beat until smooth (do not overbeat). Remove cake from the pan and place on a platter or cake stand. Ice top of cake so that it resembles a frothy pint of beer. Refrigerate leftovers.