In a large bowl, cream together the butter, brown sugar and granulated sugar until light and fluffy, about 3 minutes.

Add the egg and vanilla extract, and mix until well combined.

In a medium bowl, whisk the flour, cornstarch, baking soda, baking powder and salt. Add the dry ingredients to the wet ingredients. Stir just until no dry streaks remain.

Finally, stir in the chopped pecans, cover, and refrigerate for 30 minutes.

Roll 6 (1-inch) balls from the dough and place them evenly onto each prepared baking sheet. Gently press down the tops of the cookies, and place a pecan half on top.

Bake for 10-12 minutes or until the edges start to turn a light golden color, and the tops lose the wet appearance.

Let them cool for 5-10 minutes on the pan then transfer to a wire rack to cool completely

Serve slightly warm or at room temperature. See post for storage options.