Beat cake mix, pudding mix, eggs, water, oil and vanilla in large bowl with electric mixer on low speed for 30 seconds. Beat on medium speed for 2 minutes.
Stir in chocolate chips. Pour into greased and floured 12-cup Bundt pan.
Bake in preheated 350 F. oven for 50 to 55 minutes or until toothpick inserted in center comes out clean. Cool in pan 10 minutes. Invert cake onto wire rack. Cool completely.
For the glaze:
Mix sugar, milk and butter in small saucepan on medium heat. Stirring constantly on medium heat, bring to a boil and boil 1 minute. Remove from heat. Stir in chocolate chips and vanilla extract until chips are melted. Drizzle glaze over cooled cake.
Notes
To mix it up a bit:For the holidays substitute peppermint extract for the vanilla. Add 1 teaspoon to the cake mix and 1/2 teaspoon to the glaze. Garnish with crushed peppermints.