Heat oven to 350. Spray a 12 cup bundt pan with a light spraying of cooking spray. Dust pan lightly w/ unsweetened cocoa powder. In lg bowl, with mixer on med speed, mix cake mix, pudding mix, sugar, water, oil and applesauce until creamy.
Stir in sour cream, beat in eggs. Stir in chocolate chunks. Pour batter into pan and even it out with a spatula. Bake 1 hr, or until a toothpick inserted in center comes out clean. In my oven, it ook 50 mins.
Take cake out of oven and let cool 10 mins. In a small microwave bowl, melt butter with chocolate chips until just melted. Drizzle over cake. I sometimes like to decorate the cake with thin slices of fresh strawberries. I didn't have any available at the time I made this.