Start by preparing the chocolate pudding with 2 cups of milk as directed on the package. Set it aside.
Similarly, prepare the vanilla pudding with another 2 cups of milk.
Stir in the mint extract and food coloring into the vanilla pudding until well mixed.
Dip Oreos briefly in a small bowl with the remaining 1/2 cup milk and line them up in a 9x13 pan to create a base layer.
Spread the chocolate pudding over the Oreos and sprinkle half of the mini chocolate chips on top.
Dip more Oreos in milk, place them over the chocolate chips for a second layer.
Top with the minty vanilla pudding, spread the Cool Whip evenly, and sprinkle with the remaining chocolate chips.
For a final touch, crumble some Oreos on top and drizzle with chocolate sauce if using.