Begin by crushing about 24 Oreo cookies into fine crumbs using a food processor or a sealed bag and rolling pin. In a mixing bowl, combine the cookie crumbs with 6 tablespoons of melted unsalted butter until fully coated. Press this mixture firmly into the bottom of a 9x13 inch dish to create an even layer. Refrigerate the crust for at least 15 minutes to set.

In a large bowl, beat together 8 ounces of softened cream cheese, 1 cup of powdered sugar, and 1 teaspoon of vanilla extract until smooth and creamy, about 3 minutes with an electric mixer. Gradually mix in 2 tablespoons cocoa powder and 1 packet of milk-chocolate hot cocoa mix until well incorporated. Gently fold in 2 cups of whipped topping, creating a light and fluffy texture. Spread this chocolate mixture over the chilled crust and refrigerate for an additional 30 minutes.

In a separate bowl, whisk together 1 package of instant vanilla pudding mix and 2 cups of cold milk until it thickens, which should take about 2 minutes. Once thickened, fold in another 2 cups of whipped topping, 1 teaspoon of mint extract, and a few drops of green food coloring until evenly combined. Carefully layer this mint mixture over the chocolate layer, smoothing out the top with a spatula to create an even surface.

Cover the dish with plastic wrap or a lid, and refrigerate the Shamrock Lasagna for at least 4 hours, allowing all layers to set properly. This chilling time enhances the flavors and ensures the dessert holds its shape when sliced. If possible, letting it chill overnight will yield even better results, as the flavors meld beautifully.

When ready to serve, remove the Shamrock Lasagna from the refrigerator and top with additional whipped cream, maraschino cherries, and a sprinkle of green sprinkles for festive flair. Use a warm knife to cut through the layers cleanly, ensuring each slice highlights the contrasting colors and textures of the dessert. Enjoy!