Preheat the oven to 350°F. Line three baking sheets with parchment paper.
In a large bowl, beat the butter, brown sugar, and granulated sugar for 2-3 minutes until creamy and light.
1 1/2 cups salted butter, 1 1/2 cups light brown sugar, 1 cup (200g) granulated sugar
Add the eggs and vanilla. Mix again on medium speed until combined, stopping to scrape the bottom and sides of the bowl.
2 large eggs, 1 Tablespoon pure vanilla extract
Add the flour, black cocoa powder, 2 cups of the Oreo crumbs, baking powder, baking soda, and salt. Mix on medium-low speed just until combined and no streaks of flour remain.
3 cups (423g) all-purpose flour, 1 cup black cocoa powder, 2 1/2 cups Oreo cookie crumbs, 1 teaspoon baking powder, 1 teaspoon baking soda, 1/2 teaspoon salt
Use a large cookie scoop to portion the dough into large mounds, then roll them into balls. Roll each ball of dough in the remaining Oreo crumbs. Press to flatten slightly into thick pucks and space them a few inches apart on the prepared baking sheets, no more than 6 per baking sheet. Bake for 12-14 minutes until set around the edges but do not overbake. Let cool completely before frosting.
To make the frosting, combine the butter and cream cheese in a large mixing bowl. Beat on medium-high speed until smooth and completely combined.
1/2 cup salted butter, 6 Tablespoons cream cheese
Add the powdered sugar, vanilla extract, and cream or milk. Mix on medium-low speed until the powdered sugar is incorporated, then increase the speed to medium-high and beat for 2 minutes until smooth, creamy, and light.
4 cups powdered sugar, 2 teaspoons pure vanilla extract, 1 Tablespoon heavy cream or milk
Transfer the frosting to a piping bag or large heavy duty ziploc bag and snip a small section off the end to pipe a ribbon of frosting in concentric circles around the top of each cookie. Sprinkle with additional Oreo cookie crumbs to finish.
2 Tablespoons Oreo cookie crumbs