Preheat oven to 350°. Spray two regular sized muffin tins with cooking spray.
Whisk together flour, cocoa powders, baking soda, and salt. Set aside.
Beat butter and sugars on med-high until light and fluffy (approx. 2-3mins). Reduce speed and add eggs one at a time and vanilla. Beat until combined. Add flour mixture and mix until just combined.
Using a large cookie scoop (3 Tbsp) scoop dough into muffin tins, press down to flatten.
Bake for approx. 10-13mins or until mostly set, but still soft in the middle.
Remove from oven and immediately use a small jar or container to press firmly down in the center to create a well. Cool in pans for 10mins, loosen each slightly by twisting it in the pan. Cool for 5 more minutes then remove from pan and cool completely on a wire rack.
Oreo Cheesecake Filling:
Whip heavy cream until stiff peaks (ideally with a cold whisk and in a cold bowl).
In a separate bowl, beat cream cheese and sugar until smooth. Add Oreo cookie crumbs and beat until incorporated.
Add whipped cream into cream cheese mixture and beat until combined.
Pipe into cooled cookie cups and refrigerate until set (approx. 1-2 hours).
Sprinkle with additional Oreo cookie crumbs if desired.
Serve chilled and eat within 2-3 days. Or freeze for up to 4 weeks.
* If you don't have black cocoa powder, you can use Dutch-processed instead, but the cookies will not have the same "Oreo" taste or be as dark in color. ** If you can't find Oreo cookie crumbs, you can crush up the cookie part of the actual cookies.