Preheat the oven to the temperature specified on the brownie mix box. Mix and bake the brownie batter in an 8x8 inch pan according to the package instructions, about 20-25 minutes. Allow cooling completely.

Prepare the instant vanilla pudding according to package instructions, adding green food coloring until desired hue is achieved. Set aside in the refrigerator for about 5 minutes.

Crush the Mint Oreos in a Ziploc bag until they are coarse crumbs, then set aside in a bowl for layering.

Break the cooled brownies into bite-sized pieces and layer them in the bottom of a large trifle bowl. Add a layer of the green vanilla pudding and a generous layer of Cool Whip on top. Repeat layers as desired.

Sprinkle the crushed Mint Oreos evenly over the top layer of Cool Whip for a crunchy topping.

Cover the trifle with plastic wrap and chill it in the refrigerator for at least 1 hour before serving.