Begin by pulsing the chocolate sandwich cookies in a food processor until they turn into fine crumbs. In a mixing bowl, combine the crumbs with melted unsalted butter, mixing until fully combined. Press this mixture evenly into the bottom of a greased 9x13 inch dish, until it forms a firm crust. Chill this crust in the refrigerator for about 10 minutes to set.

In a large mixing bowl, beat the softened cream cheese until smooth using an electric mixer, ensuring there are no lumps. Gradually add in powdered sugar, continuing to mix until well incorporated. Then, fold in whipped topping gently until the mixture is light and airy. Spread this creamy mixture evenly over the prepared crust, covering it completely and smoothing out the top.

Carefully spoon the strawberry pie filling over the cream cheese layer, spreading it gently to avoid mixing the layers. Follow with the blueberry pie filling, ensuring the layers are distinct and visually appealing.

Using the remaining whipped topping, create decorative swirls on the top of the filling layers. Sprinkle star-shaped sprinkles evenly across the surface. Once decorated, cover the dish with plastic wrap, and chill in the refrigerator for at least 4 hours.

When ready to serve, remove from the refrigerator and use a sharp knife dipped in hot water to cut clean slices. Enjoy this eye-catching dessert cold.