Preheat the oven to 350 degrees Fahrenheit and spray a 9-inch springform pan or round cake baking dish with cooking spray.
In a large bowl, combine the chocolate chip cookie mix, salted butter, large egg, and water together. Mix together until completely combined and a dough forms.
Fold in ⅓ cup of the divided easter Cadbury eggs, ⅓ cup of the divided easter M&Ms, and ⅓ cup of the white chocolate chips. Mix until the candy is evenly distributed.
Scoop the cookie batter into the bottom of the prepared cake pan and spread it as evenly as possible.
Bake in the oven for 30-35 minutes or until the middle of the cookie cake starts to set and turn golden brown.
Once the cookie cake is done baking, remove it from the oven and, while still warm, press the rest of the Easter Cadbury eggs, M&Ms, and chocolate chips into the top of the cookie cake.
Set the cookie cake aside and let it cool completely.
Once the cake has cooled, gently remove the cake from the cake pan and onto a plate or cake stand. Try not to flip the cookie over, as the eggs and M&Ms may fall off.
Spoon the vanilla frosting into a piping bag with your desired tip (I used a 1M Wilton tip).
Pipe frosting onto the edge of the cookie cake.
Sprinkle the entire cake with festive sprinkles.
Notes
Storage:
To Store: Cover and store this cookie cake at room temperature for up to three days. After that, the frosting and cookie cake need to be refrigerated for up to three weeks. Make sure to keep it in an airtight container for best results.
To Freeze: To freeze this cake, place in in a freezer-safe container and freeze for 2-3 months.
Tips:
You can make this for any holiday by swapping out the candy and sprinkles.
Do not over bake your Easter cookie cake. If you leave it in the oven too long, it will be dried out and crumbly.
Do not remove the cookie cake from the pan too early or it will fall apart.
Let your cookie cake cool completely before frosting. If you pipe the frosting on while the cake is warm, it’ll become a melted mess!