Preheat your oven to 350°F (175°C). Grease a 9-inch round cake pan and line the bottom with parchment paper to ensure easy removal later.
In a large bowl, sift together the flour, cocoa powder, baking powder, baking soda, and salt. This ensures an even distribution of leavening agents and prevents lumps.
Using your electric mixer, beat the softened butter and granulated sugar until light and fluffy. This will take about 3-4 minutes and is key for a tender crumb.
Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract for that aromatic touch.
Begin adding the dry ingredients in three parts, alternating with the milk in two parts. Start and end with the dry ingredients. Mix gently after each addition until just combined; don’t overmix or the cake will be tough.
Gently fold in 1 cup of crushed Oreo cookies with a spatula. Be careful to keep the batter light and airy.
Pour the batter into the prepared cake pan and smooth the top. Bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean. Let the cake cool in the pan for 10 minutes, then transfer it to a cooling rack.
In a chilled bowl, whip the heavy cream, powdered sugar, and vanilla extract until stiff peaks form. This fluffy frosting will complement the chocolate cake beautifully.
Once the cake is completely cool, spread the whipped cream frosting evenly over the top and sides. Sprinkle additional crushed Oreo cookies on top for that extra cookies and cream flair.