In a large mixing bowl, add in butter and beat on low for 1-2 minutes.
Add in the sugars and beat on medium until well combined. This will take about 2-3 minutes. Scrape down the sides.
Add in the egg, vanilla, and maple extract and beat on high until light and fluffy. Scrape down the sides.
Add in the flour, cornstarch, and baking soda. Mix on medium until just combined. The original recipe called for 1 cup of bread flour and 1 cup of all-purpose flour, but all I had was all-purpose flour. The cookies weren't as dense as the original cookies.
Scoop the dough with a small cookie scoop. I got 15 dough balls out of this recipe. Place the cookie dough balls on a plate and cover with plastic wrap. Refrigerate for at least 2 hours before baking them.
Preheat oven to 350 degrees. Line the baking sheet with parchment paper.
Place 6 cookies at a time on the baking sheet and place them in the oven for 10 minutes or until they are done.
Let cool for 10 minutes on the baking sheet and then place on a cooling rack to finish cooling.