Preheat the oven to 350°F.
In a large bowl, stir together cake mix, pudding mix, eggs, sour cream, oil, chocolate chips, and peanut butter chips.
Spray a large tube pan or bundt pan with non-stick spray.
Spread batter evenly into prepared pan.
Bake for 40-45 minutes, or until a toothpick inserted near the center comes out clean.
Remove pan to a wire rack to cool for 10 minutes, then invert the cake onto the wire rack to cool completely.
In a small bowl, combine baking chocolate, heavy cream, and butter.
Microwave on high at 30-second intervals until chocolate is melted and the mixture is smooth when stirred with a whisk.
Pour over cooled bundt cake.
In another small bowl, microwave peanut butter for 30 seconds, or until melted and thin. Drizzle over cake.
Allow 10-15 minutes for toppings to set. Cut and serve.