Preheat oven to 350-F. Grease and flour a 12-inch bundt pan.
In a large bowl, combine the cake mix and pudding and set aside.
In another bowl (mixing bowl), beat the eggs, stout, and oil until blended. Pour in the dry mixture and beat for 2 minutes.
Stir in the chocolate chips. Pour the batter into the prepared pan.
Bake the cake for 55 minutes or until a toothpick inserted comes out clean. While the cake is baking, make the Guinness Glaze (because it needs time to cool).
Remove the cake and allow to rest for 10 minutes. Invert the cake onto a cake plate. While the cake is still warm, brush about 1/3 of the glaze over the cake.
Allow the cake to cool completely, and then drizzle the remaining 2/3 glaze over the cake.
Make the glaze:
Combine the butter, sugar, and stout beer and water in a saucepan. Cook over medium heat, stirring, until melted.
Remove from the heat and stir in the bittersweet chocolate pieces and stir until melted and smooth.
COOL THE GLAZE to room temperature before using.
Make the whipped cream:
Whip the heavy whipping cream until thick. Add in the powdered sugar and vanilla and gently mix together.
Slice the cake into individual servings. Top with a dab of fresh whipped cream.
Sprinkle on each serving the semisweet or bittersweet chocolate for garnish.
Notes
TIP for shaved chocolate: Either finely chop the chocolate with a knife, or use a cheese grater.