Preheat your oven to 350°F (175°C).
Grease and flour two 9-inch round cake pans.
In a large mixing bowl, combine the dry ingredients: flour, sugar, cocoa powder, baking powder, baking soda, and salt.
In a separate bowl, whisk together the eggs, milk, oil, and vanilla.
Gradually add the wet ingredients to the dry ingredients, mixing until just combined.
Gently fold in crushed Oreo cookies into the batter.
Divide the batter evenly between the prepared cake pans and smooth the tops.
Bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
Allow the cakes to cool in the pans for 10 minutes, then transfer to wire racks to cool completely.
While the cake layers cool, make the frosting by beating the heavy cream until soft peaks form.
Gradually add the powdered sugar while continuing to beat the whipped cream.
Once fully whipped and fluffy, fold in crushed Oreo cookies to the frosting.
Assemble the cake by placing one layer on a serving plate, spreading a generous amount of frosting on top, then adding the second layer.
Frost the top and sides of the cake with the remaining frosting, decorating as desired.