Preheat your oven to 350°F (175°C) and grease your cake pans with butter or nonstick spray.

In a large bowl, mix together the dry ingredients: sugar, flour, cocoa powder, baking powder, baking soda, and salt.

Add the eggs, milk, vegetable oil, and vanilla extract to the dry mixture. Beat with an electric mixer on medium speed for 2 minutes until combined.

Pour in the boiling water slowly and stir until well-integrated. The batter will be quite thin.

Distribute the batter evenly between the prepared pans and bake for 30-35 minutes. The cakes are done when a toothpick inserted into the center comes out clean.

Allow the cakes to cool in the pans for 10 minutes, then transfer to wire racks to cool completely.

Meanwhile, prepare the cream cheese filling: Beat together softened cream cheese, butter, and vanilla extract until creamy. Gradually add powdered sugar and mix until smooth.

For the Chocolate Cream Cheese Buttercream, blend softened butter and cream cheese until fluffy. Gradually mix in cocoa powder and powdered sugar, adding milk until you reach your desired consistency.

Once the cakes are cooled, assemble: Place one cake layer on a serving plate, spread a layer of cream cheese filling, top with the second cake layer, and frost the entire cake with the chocolate cream cheese buttercream.