When doubling a recipe with cornstarch do you double the cornstarch?

No. When doubling a recipe with cornstarch, do not double the amount of cornstarch. Cornstarch acts as a thickening agent and doubling its quantity can make the dish overly dense and gummy. For sauces, soups, and stews, start by adding only half the indicated amount of cornstarch, gradually increase it if needed while ensuring not to exceed the original.