Preheat oven to 350°F (175°C). Lightly grease a 12-cup muffin tin.

In a large bowl, cream together butter, granulated sugar, and brown sugar until light and fluffy.

Beat in the egg and vanilla until smooth.

In a separate bowl, whisk together flour, cocoa powder, baking soda, and salt. Gradually mix into the wet ingredients until just combined.

Scoop about 1 tablespoon of dough into each muffin cup. Bake 10–12 minutes until set but still soft.

Immediately press down the centers with the back of a spoon to form cups. Cool completely before removing from the tin.

In a medium bowl, beat cream cheese until smooth. Add powdered sugar and mix until creamy.

Slowly add heavy cream and whip until thick and fluffy. Fold in crushed Oreos.

Spoon or pipe filling into cooled cookie cups. Garnish with more crushed Oreos. Chill at least 1 hour before serving.