Grandma's Chocolate Lover's Bundt Cake

This is the cake recipe Grandma gave us each with a bundt pan. I've made it a lot, so there are also notes with things I've learned in the process!

INGREDIENTS
1 pkg. yellow cake mix
1 pkg. instant chocolate pudding (3.9 oz.)
1/2 c. sugar
1 c. sour cream (8 oz.)
3/4 c. vegetable oil
3/4 c. water
4 eggs
1 c. semisweet chocolate chips (I use mini chips and they don't all sink to the bottom!)
6 squares white baking chocolate (1 oz. each)

DIRECTIONS
In a mixing bowl, combine dry cake mix, pudding mix, and sugar. Add the sour cream, oil and water; mix well. Add eggs, one at a time, beating well after each addition. Stir in chocolate chips. Pour into a greased and floured (it has to be VERY well greased and floured or I use "Cake Release" which also works really well) 12-cup fluted tube pan (the smaller "bundt" pans like grandma bought us are not large enough and the cake will spill over!). Bake at 350° for 50-55 minutes or until a toothpick inserted near the center comes out clean (sometimes longer, just keep checking). Cool for 10 minutes; remove from pan to a wire rack to cool completely. In a microwave or double boiler, melt the white chocolate; drizzle over cake. Yield: 12-16 servings.