• Preheat oven to 350 degrees and grease a 9" round cake pan or springform pan.
• In a large bowl cream the butter and sugars together on medium speed until fluffy and light in color. Mix in eggs and vanilla until combined.
• Add the flour, baking soda and salt. On low speed, slowly mix into the wet ingredients. Stir in chocolate chips.
• Press dough into prepared pan and bake for 18-23 minutes or until the edges just start to turn brown and center is set but still soft. Let cookie cool completely in pan.

FOR THE FROSTING:

• In a large bowl, cream together the butter, and vanilla. Blend in the sugar, one cup at a time, beating well after each addition. Beat in the milk, 1 tablespoon at a time until desired consistency is met (you might not need it all). Continue mixing until light and fluffy. Keep icing covered until ready to decorate. Using a large star tip decorate the cooled cookie cake. Add sprinkles and extra chocolate chips if desired. Store and serve at room temperature.