Chocolate chip cookie cake - chinese grandma

Ingredients

• 1 cup (2 sticks) butter, softened at room temperature
• 1/2 cup granulated sugar
• 1 3/4 cups firmly packed light brown sugar
• 2 eggs
• 2 teaspoons vanilla
• 3 1/2 cups all-purpose flour
• 1 1/2 teaspoons baking soda
• 1/4 teaspoon salt (3/4 teaspoon if using unsalted butter)
• 16 ounces (2 2/3 cups) chocolate chips
• 1/2 teaspoon good quality salt, for sprinkling on top before baking (optional)