For the cake:

1. Preheat oven to 350°F.
2. Combine cake mix together with all of the ingredients: pudding mix, eggs, coffee, vegetable oil, sour cream, espresso powder and vanilla. Beat until all ingredients are well combined, scraping the bowl as needed.
3. Bake cake in a 9x13-inch pan for 28-32 minutes. Check for doneness by inserting a toothpick into the middle of the cake. If the toothpick comes out clean, you cake is done. Allow to cool for at least 30 minutes.
4. While the cake is still warm, take the end of a wooden spoon or another round object and poke holes all over the top of your cake.
5. For the filling: In a small mixing bowl, combine the chocolate pudding, milk and coffee and whisk until the pudding mix is dissolved. Before the pudding sets (do not refrigerate), pour it over top of the cake, and spread with a spatula to fill in all the holes.
6. Refrigerate the cake for at least 10-15 minutes until the pudding is set and the cake is completely cooled while you prepare the topping.

For the topping:

1. Put the bowl and whisk attachment in the freezer for 5-10 minutes to get them really cold.
2. Prepare the espresso. Heat the water in a microwave-safe dish and add the instant espresso powder, stirring until it’s dissolved. Place the espresso in the freezer to cool it down.
3. Pour the heavy whipping cream into the chilled bowl and beat on medium speed for about 3 minutes until the cream starts to thicken. Slowly added the cooled espresso while you’re still whipping the cream until it’s combined.
4. Turn the mixer down to low speed and slowly add the powdered sugar. Once the sugar is incorporated, turn the mixer back to a higher speed and beak until stiff peaks form. Fold in the crushed Oreos and spread the whipped cream over top of the cooled cake.
5. This cake must be refrigerated. Garnish with hot fudge sauce and more crumbled Oreos.