cookie cake recipe

Here’s a delicious and easy-to-make cookie cake recipe for you: Ingredients: ¾ cup unsalted butter (softened to room temperature) 1 cup dark brown sugar (or packed light brown sugar) 1 large egg (+ 1 egg yolk) 2 teaspoons pure vanilla extract 2 cups all-purpose flour (spooned & leveled) 2 teaspoons cornstarch 1 teaspoon baking soda ½ teaspoon salt 1½ cups semi-sweet chocolate chips (divided) Chocolate buttercream (optional: for topping) Thanks for watching.