Preheat your oven to 350°F (175°C) and grease and line two 8-inch round cake pans with parchment paper.
In a large mixing bowl, combine the flour, sugar, cocoa, baking powder, baking soda, and salt. Mix until well combined.
Add the eggs, milk, vegetable oil, and vanilla extract to the dry ingredients. Mix on medium speed until the batter is smooth.
Stir in the boiling water. The batter will be thin, but that's okay. It's what makes the cake moist and delicious.
Pour the batter evenly into the prepared pans and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cakes to cool in the pans for 10 minutes, then transfer them to a cooling rack to cool completely.
In a mixing bowl, beat the softened butter until it's creamy and smooth.
Gradually add the powdered sugar and cocoa powder, mixing until well combined.
Stir in the vanilla extract and enough milk to achieve your desired frosting consistency.
Crush the Oreo cookies (you can do this by placing them in a zip-top bag and using a rolling pin) and fold them into the frosting.
Place one cake layer on your cake stand or platter.
Spread a generous layer of Oreo frosting on top of the first layer.
Place the second cake layer on top and frost the entire cake with the remaining Oreo frosting.
You can decorate the cake with additional Oreo crumbs or even whole Oreo cookies for a stunning presentation.
Slice and serve this masterpiece. Enjoy!