Sift together cake and pudding mixes into a large mixing bowl.
Make a well in the center and add eggs, 2 sticks melted butter, sour cream, coffee, and 1 teaspoon vanilla.
Beat on low speed until blended then increase speed to medium-high and beat for 4 minutes.
Stir in 2 cups chocolate chips.
Pour batter into well greased 12-cup bundt or tube pan and bake at 325 degrees for 50-55 minutes or until cake springs back when touched.
Cool cake in pan for 10 minutes then turn out onto wire rack to cool completely.
For glaze, combine 3 tablespoons softened butter, remaining 3/4 cup chocolate chips, and corn syrup in a small saucepan over low heat. Stir constantly until chocolate and butter are melted. Remove from heat and stir in remaining 1/4 teaspoon vanilla. Spread over cooled cake.
Serve with whipped cream or ice cream.
Suggestion: Tossing chocolate chips with 1 tablespoon all-purpose flour before adding to cake batter will prevent them from sinking to bottom of pan during baking.