For the cake:

Preheat the oven to 350º F. Lightly spray a bundt pan with the cooking spray and dust with flour. Add the cake mix, pudding, milk, oil, sour cream and eggs to the bowl of a stand mixer fitted with the paddle and beat on low, gradually increasing the speed to medium, until all of the ingredients are thoroughly blended, about 2 minutes. Fold the chips in by hand with a rubber spatula. Transfer the batter to the prepared pan and smooth the top. Bake in the center of the oven for at least 1 hour or until a skewer inserted into the middle of the cake comes out clean. Remove from the oven and place on a cooling rack in the pan for 15 minutes. Then remove from the pan and cool completely. This cake stays moist for several days if it is not devoured before that but it also freezes quite well.

For the ganache:

Place the chocolate chips, espresso, butter and salt in a large heat proof bowl over a pot of simmering water. Stir occasionally until the chocolate is completely melted. Remove the bowl from the heat and pour in the hot cream. Allow to sit for a minute or two and then stir carefully in concentric circles from the center out until the cream is completely blended into the chocolate mixture. Allow to cool to lukewarm before drizzling over the cake. Save any extra ganache in the refrigerator for another use.

To finish transfer the cake to a serving plate and drizzle with the ganache if desired.