Preheat your oven as per package instructions for the brownie mix. In a mixing bowl, combine the brownie mix, eggs, and oil or butter until smooth. Pour the batter into a greased baking dish and spread evenly. Bake according to package directions until a toothpick inserted comes out with a few moist crumbs, usually about 20-25 minutes. Allow the brownies to cool completely before assembly.

While the brownies cool, in a large bowl, whisk together the instant vanilla pudding mix and the milk until well combined and thickened, typically about 2 minutes. Add a few drops of green food coloring and stir until you reach your desired shade.

Grab a sealed Ziploc bag and add the Mint Oreos. Using a rolling pin, crush the cookies until you have small pieces resembling coarse crumbs, keeping some larger chunks aside for the top layer.

In a large trifle bowl or individual serving cups, start layering your trifle. Begin with a layer of brownie pieces at the bottom, followed by a layer of prepared vanilla pudding, then Cool Whip, and top with crushed Mint Oreos. Repeat layers until the bowl is filled to your desired height.

Finish with a final layer of brownie pieces topped with vanilla pudding, and scatter the remaining crushed Oreos over the top for a festive finish.

Cover the trifle with plastic wrap and refrigerate for at least one hour to allow the flavors to meld.