Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
In a large mixing bowl, combine the flour, sugar, cocoa powder, baking powder, baking soda, and salt. Whisk until well blended.
Add the eggs, milk, vegetable oil, and vanilla extract to the dry ingredients. Beat on medium speed for 2 minutes.
Stir in the boiling water until the batter is smooth. Fold in the crushed cookies gently.
Pour the batter evenly into the prepared cake pans. 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 remove from pans and transfer to a wire rack to cool completely.
In a medium bowl, whip the heavy cream with powdered sugar and vanilla extract until stiff peaks form.
Once the cakes are completely cooled, place one layer on a serving plate. Spread a layer of whipped cream on top and sprinkle with more crushed cookies.
Top with the second cake layer and frost the top and sides with the remaining whipped cream. Garnish with additional crushed cookies.