Heat oven to 350 degrees F. Coat 12-cup bundt pan with nonstick cooking spray.
Combine flour, cocoa, pudding mix, baking powder and salt in bowl.
Beat butter and sugar until light, 2 minutes. Beat in eggs, one at a time, beating well after each. Alternately beat in flour mixture and the milk, beginning and ending with flour mixture. Stir in vanilla and pour into prepared pan.
Bake at 350 degrees for 46 to 50 minutes or until cake springs back when pressed. Cool cake in pan 15 minutes. Remove cake from pan to rack; let cool completely.
Place cream in small saucepan. Bring just to a boil over medium heat, about 3 minutes. Add chocolate; stir until melted and smooth. Return to low heat, if needed. Spoon over cake; let stand.
Combine white chocolate and oil in small microwave-safe bowl. Microwave about 1 minute, stirring halfway through, until melted. Stir until smooth. Let cool slightly, 5 to 10 minutes. Drizzle over Chocolate Glaze; let set. Makes 16 servings.