Cake: In large bowl, combine cake mix, eggs, orange juice, cooking oil and pudding mix. Blend at low speed for 1 minutes. Beat at high speed 3 more minutes. Pour two thirds of the batter into a greased and floured dozen Bundt Pan. Add chocolate syrup to remaining third of the batter and mix at medium speed until well blended. Pour over top of batter in pan. Marbleize by cutting through batter with knife. Bake at 180ºC . for 55-60 minutes or until cake tests done. Cool in pan 10-15 minutes; turn out on wire rack or serving plate to complete cooling. Top with Chocolate Glaze. Glaze: In small bowl, combine sugar, cocoa, and butter. Add vanilla; add milk gradually to achieve desired consistency and stir until smooth.