Preheat your oven to 350°F (175°C) and line a 9x9 inch pan with parchment paper.
In a stand mixer bowl, combine the brownie mix, eggs, oil, and milk. Mix on medium speed until smooth.
Pour the brownie batter into the prepared pan.
Arrange Oreo cookies on top of the brownie batter until the surface is covered.
Bake for 25-30 minutes.
Let the brownies cool completely.
In a bowl, mix the white or vanilla frosting with the orange filling from about 10 Oreo cookies. Add 1 teaspoon of orange food coloring gel and mix well. Adjust the color with more gel if needed.
Once the brownies are cooled, spread the orange frosting over the top and refrigerate for 30 minutes.
Remove from the refrigerator and frost with the chocolate frosting. Crumble the remaining Oreo cookies on top.
Cut the brownies into 3x2 inch squares and serve immediately. Enjoy!
Notes
Notes: For a more intense orange color, add additional food coloring gel until the desired shade is reached.