1/2 cup unsalted butter room temp1/2 cup creamy peanut butter1/2 cup imperial sugar extra fine granulated sugar1/2 cup imperial sugar light brown sugar1 egg1 1/2 teaspoons vanilla1 teaspoon cornstarch1/2 teaspoon baking soda1/2 teaspoon baking powder1/2 teaspoon kosher salt1 cup