Preheat oven to 325 degrees. Grease a 10-inch bundt pan with butter and lightly dust with flour; set aside.
In the bowl of a standing mixer, using the paddle attachment, combine cake mix, pudding mix, water, vegetable oil, and eggs. Mix on low for 30 seconds until combined, increase speed to medium and beat until smooth, about 1 minute. Scrape the sides of the bowl to evenly incorporate ingredients. Sir in 2 cups chocolate chips and pour the batter into the prepared pan.
Bake 50-55 minutes or until the cake is set and springs lightly when touched. Cool for 10 minutes, invert the pan onto a wire cooling rack. Cool completely before frosting.
In a small glass bowl, combine remaining chocolate chips and whipping cream. Microwave 30 seconds, stir, repeat until melted. Drizzle over top of cake and serve.