Chocolate Chip Cookie Pizza

all-purpose flour

cornstarch (aka cornflour)

baking soda

salt

or 170g) unsalted butter, softened to room temperature

packed light or dark brown sugar

granulated sugar

large egg, at room temperature

pure vanilla extract

and 1/4 cup (225g) semi-sweet chocolate chips

-inch pizza pan (one with a lip so there's no spill over the edges-- I like this one and this one)