Preheat oven to 350°F (180° C).
In a stand mixer or with an electric hand mixer, cream together the butter, granulated sugar, and brown sugar.
3/4 cups (167g) salted butter, 1/3 cup (76g) granulated sugar, 3/4 cup (185g) brown sugar
Add the egg and vanilla. Mix until light in color and creamy.
1 eggs, 1/2 Tbsp vanilla
Next, add in the dry ingredients (flour, black cocoa, crushed oreos, baking soda, baking powder and salt) and mix into the dough until completely combined.
1 1/3 cups (202g) all-purpose flour, 1/2 cup (60g) black cocoa powder, 1 cup (88g) crushed oreos (approx 20 oreos, crushed), 1 tsp baking soda, 1/2 tsp baking powder, 1/4 tsp salt
Portion out the dough into 1 1/2 Tbsp portions (#40 scoop). Roll into a ball and arrange on a cookie sheet. Press down slightly on the cookie dough, flattening it into what looks like a hockey puck.
Bake for 9-12 minutes, until the cookies are no longer glossy on the top.
Allow the cookies to cool on the pan for 15 minutes before frosting.
While the cookies are cooling, make the frosting by whipping the butter, cream cheese, and vanilla until smooth.
3/4 cups (167g) salted butter, 4 oz cream cheese, room temperature, 1 tsp vanilla
Add the powdered sugar, one cup at a time. Make sure it is completely incorporated before adding the next cup.
2 cups (214g) powdered sugar
If needed, add milk a tsp at a time until you've reached your desired consistency.
milk to thin, if needed
Add the frosting to a piping bag fit with a small round piping tip. Pipe the frosting onto the warm cookies in a spiral. Start in the center of the cookie and work your way out.
Sprinkle extra crushed Oreos on top of the frosting, if desired. Serve warm!
Store in an air tight container either in the fridge or on the counter for 3 days.