For the Cakes:

1. Preheat the oven to 350°F. In a large Ziploc bag, crush the Oreos into small pieces using a rolling pin or something similar. 
2. In a large mixing bowl, combine the sugar, vegetable oil, eggs and vanilla extract. Beat on medium speed until the eggs and oil are well incorporated and the batter is lighter in color, about 2 minutes. Scrape down the bowl as needed. Next mix in the sour cream and beat until well combined.
3. In a separate bowl, combine the remaining dry ingredients. Alternate adding half the dry ingredients and half the milk at a time and mix just until the flour starts to incorporate. Use a spatula to scrape down the sides of the bowl and stir the batter from the bottom to the top to ensure it’s well mixed. Fold the crushed Oreos into the cupcake batter.
4. Pour the batter into a 9×13-inch baking pan. Bake at 350°F for 26-28 minutes. Test the cake for doneness by inserting a toothpick into the center of the cake. If the toothpick comes out clean, the cake is done. Cool Completely.

For the Filling: 

1. Once the cake has cooled, use a wooden spoon or another round object and poke holes over the top of the cake.
2. In a small mixing bowl, combine the instant pudding with the milk and whisk together until the powdered mix is dissolved.
3. Pour the liquid pudding mix over top of the cake, try to fill the holes with the pudding mix. Refrigerate the cake until the pudding is firm, about 10 minutes or so.

For the Topping: 

1. Place the mixing bowl and whisk attachment in the freezer for 5 to 10 minutes to chill
2. Pour the heavy whipping cream into the chilled bowl and use an electric mixer to beat the heavy cream on medium-high speed until soft peaks form.
3. Slowly add the powdered sugar and continue beating on high speed until stiff peaks start to form. Spread the whipped cream over the top of the cake. Keep refrigerated. Serve with hot fudge sauce and crushed Oreos.