In the bowl of a stand mixer, affixed with the paddle attachment, add the butter and mix on medium-high speed. Once creamy, add the brown sugar and mix until light and fluffy. Slow the mixer and add the egg and the vanilla extract. Mix until combined. With the mixer on low, add the flour, salt, baking soda, baking powder, cornstarch and nutmeg. Mix until just combined.

Remove the bowl from the mixer and wrap the cookie dough in plastic wrap, to chill in the refrigerator for 2-3 hours (minimum).

Once cookie dough has chilled, preheat oven to 350-degrees and line three cookie sheets with parchment paper or silpats. Add the 1/4 cup of white sugar to a small bowl. Use a standard sized cookie scooper to scoop cookie dough balls. Roll the cookie dough balls in the sugar and place on the prepared cookie sheet. Allow enough space in between cookie dough balls for the cookies to spread during baking.

Bake cookies, one sheet at a time, in a 350-degree oven for 10-11 minutes. Allow cookies to set on the cookie sheet for 10-minutes before transferring to a wire rack to finish cooling completely.