Let the cookie base cool COMPLETELY before attempting the next step. If the base is warm, the frosting will melt and be a mess! Use parchment paper or cooking spray on your baking sheet if you are worried about your cookie sticking. Choose any kind of berries that you like – make it pretty, however you prefer! Add a little vanilla extract to the frosting place of the lemon if you wish. Use a pizza cutter to make it easy to slice and serve.