Preheat oven to 350 degrees F. Generously butter a 10-cup Bundt pan, dust with flour, and shake out excess.
Whisk together flour, baking soda, cinnamon, cloves and salt in a medium bowl and set aside. Whisk together the dark German beer, molasses and ginger in a medium bowl and set aside.
Combine butter, sugar and egg in a large bowl and beat at medium speed with a mixer for 2 minutes, or until mixture is light and fluffy. In 3 additions, alternately beat in flour mixture and beer mixture at low speed until batter is smooth. Stir in chocolate and crystallized ginger. Spoon batter into prepared pan, smoothing top of batter.
Bake 30 to 35 minutes or until a wooden toothpick inserted in center of cake comes out clean. Cool in pan on a wire rack 10 minutes. Remove cake from pan and cool completely on a wire rack. Dust cake with confectioners' sugar, if desired.