If you want a cookie cake, there's no need to run to the grocery store or local bakery. Cookie cakes don't require special recipes or extravagant baking techniques. As long as you have your favorite premade or homemade dough on hand, you can make a cookie cake from the comfort of your kitchen.
Preheat the oven to 350 degrees Fahrenheit; the rack should be in the center of the oven.
Place the cookie dough onto a large, non-stick baking pan, or spray a non-stick pan with an even layer of cooking spray. Use a 13-by-9 inch half sheet or similar large baking pan or a pizza pan that is at least 2 inches deep.
Press the cookie dough onto the pan in an even, 1/2-inch thick layer. Place a sheet of plastic wrap over the dough as you press it flat to stop if from sticking to your fingers.
Transfer the baking pan to the preheated oven and bake the cookie cake for 30 to 40 minutes. Test the cake's doneness by pressing your finger lightly on the center of it. It is done when it feels more solid than soft.
Remove the baking pan from the oven and place it on a wire rack to cool. Allow the cookie cake to cool for 30 minutes; as it cools, the cookie cake will continue to firm.
Decorate the cooled cookie cake with frosting, if you wish.
Slice the cookie cake with a pizza cutter and carefully remove the pieces from the baking pan to serve.