How to Make It
Preheat oven to 350°F. Grease and flour a 12-cup Bundt pan.
Whisk cake and pudding mixes in a large bowl. In another large bowl, with an electric mixer on medium speed, beat sour cream until lightened, about 3 minutes. Beat in eggs until well combined. Add oil and 1/2 cup warm water; beat until smooth. Reduce speed to low. Beat in cake mix mixture in 2 batches until no lumps remain, about 3 minutes. Stir in 2 cups chocolate chips.
Bake until a tester inserted into cake comes out clean, about 1 hour. Let cake cool on a wire rack for 10 minutes, then remove from pan and allow to cool completely on wire rack.
Make glaze: Stir together heavy cream and remaining 1/2 cup chocolate chips in a microwavable cup. Microwave for 1 minute at 50 percent power. Whisk until smooth. Pour over cake. Serve.