Preheat your oven and prepare the brownie mix according to the instructions. Bake for 20-25 minutes until a toothpick comes out with a few moist crumbs. Allow to cool, then cut into pieces.

Prepare the instant vanilla pudding by mixing the pudding mix with milk. Add green food coloring if desired. Whisk until thickened.

Crush the Mint Oreos in a sealed plastic bag using a rolling pin. Set aside in a bowl.

Layer the trifle in a bowl or cups, starting with brownies, followed by pudding, Cool Whip, and crushed Oreos. Repeat layers, finishing with Cool Whip and crushed Oreos on top.

Cover the assembled trifle with plastic wrap and chill in the refrigerator for at least 2 hours before serving.