Prepare the Pudding:
In a large bowl, whisk together the instant vanilla pudding mix and milk. Let stand for 5 minutes to thicken.

Make the Cream Cheese Mixture:
In a separate bowl, beat the softened cream cheese until smooth. Gradually add the powdered sugar and beat until well combined.

Combine Pudding and Cream Cheese:
Gently fold the cream cheese mixture into the vanilla pudding until well combined.

Fold in Whipped Topping:
Gently fold in the thawed whipped topping until the mixture is light and fluffy.

Layer the Casserole:
In a 9×13 inch baking dish, spread a layer of crushed Oreo cookies.

Add Filling and Toppings:
Pour half of the pudding mixture over the Oreo cookies. Sprinkle with some of the Easter candies. Repeat the layers with the remaining Oreo cookies, pudding mixture, and Easter candies.

Chill to Perfection:
Cover and refrigerate for at least 4 hours, or preferably overnight, to allow the flavors to meld and the casserole to set.

Garnish and Serve:
Before serving, garnish with additional crushed Oreo cookies and Easter candies, if desired. Serve chilled and enjoy this festive Easter Oreo Cookie Casserole!