Preheat your oven to 350°F (175°C) and prepare a baking sheet with parchment paper.

In a large mixing bowl, combine the butter, brown sugar, and granulated sugar until pale and fluffy.

Add maple syrup, egg, and vanilla extract to the creamed mixture and blend until smooth.

In another bowl, whisk together the flour, cornstarch, baking soda, and salt to blend well.

Gradually fold the dry mixture into the wet mixture until just combined.

Drop rounded balls of dough onto the prepared baking sheet, spacing them at least 2 inches apart.

Bake for 10 to 12 minutes, watching for golden brown edges and slightly underdone centers.

Let the cookies rest on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.