First, preheat your oven to 350F.
Spray 3 round cake pans with cooking spray
Dust the pans lightly with flour, set aside.
In a Large mixing bowl or kitchenaid mixer combine the Flour, Hersheys cocoa, sugar, baking powder, baking soda, and the salt.
Add in the milk, oil, eggs and the vanilla extract & mix until everything is thoroughly incorporated. Once all combined, stir in the boiling water last; mix again, the batter will be very thin.
Pour the batter evenly in each of the sprayed/floured cake pans
Bake for 30-35 minutes, or until a toothpick inserted in the center of each layer comes out clean. Once fully baked, remove from oven & allow the 3 cakes to cool for at least 10-15 minutes before removing them.
Once removed, transfer to a wire rack to finish cooling completely.
I always use a cake leveler to make sure the layers are even, you can also use a serrated knife
While they finish cooling, prepare your frostings.
Whip the cream cheese & the butter with an electric mixer on high speed for about 30 seconds. Once combined begin adding in 1/2 cup of powdered sugar at time, making sure each half cup is fully incorporated before mixing in another 1/2 cup., add in the vanilla extract & whip one last time for about 30 more seconds on high and beat one minute more until nice & fluffy
In a large bowl beat the butter & cream cheese with an electric mixer and begin adding in the powdered sugar 1/2 cup at a time again
add in the cocoa and the milk & vanilla
Whip all of the ingredients until they are thoroughly incorporated
Beat at High speed for about one minute or until fluffy.
Once you are ready to assemble the cake
Level the cakes with a cake leveler to assure perfect stacking of the cake layers
Place the bottom layer on a cake plate.
Spread 3/4 cup of the cream cheese buttercream filling over the bottom cake layer
Top with the second leveled layer and repeat the process.
Lastly, top with the third layer.
Frost just the very top with the remaining Whipped cream cheese buttercream & refrigerate for about 15 minutes
Finally, remove from the refrigerator & frost the top layer gently with the chocolate cream cheese buttercream & all over the sides of the cake.
Refrigerate until ready to serve.