Here's the recipe:
8 tbsp. unsalted butter
¾ cup sugar
1 cup all-purpose flour
½ cup unsweetened dark cocoa powder
½ tsp. salt
2 large eggs
¼ cup milk
1½ cups coarsely chopped Oreo cookies
6 oz. cream cheese, at room temperature
½ cup powdered sugar
1 ½ tsp. vanilla extract
Preheat the oven to 350˚ F. Line an 8×8″ baking pan with aluminum foil and spray with Pam.
In a small saucepan over medium heat, combine the butter and sugar. Bring to a boil, whisking frequently. Boil for 1 minute, then remove from the heat and set aside to cool slightly.
In a medium mixing bowl, combine the flour, cocoa powder and salt; whisk together to combine. Add the eggs to the pan with the butter-sugar mixture and whisk until combined. Whisk in the milk. Transfer the wet ingredients to the bowl with the dry ingredients and mix until just incorporated. Fold in the Oreo pieces. Spread the batter into the prepared pan.
In another bowl, combine the cream cheese, powdered sugar, and vanilla Beat with a mixer on medium-high speed until smooth. Drop the cream cheese mixture over the brownie batter in dollops. Use the blade of a knife to gently swirl the cream cheese mixture together with the brownie batter, creating a marble effect.
Bake for about 22-24 minutes (mine required longer, like 30 minutes). Transfer the pan to a wire rack and let cool completely before slicing and serving.