Place a rack in the centre of your oven and preheat oven to 350ºF.
Line 2 baking sheets with parchment paper.
In the bowl of your stand mixer cream the softened butter and brown sugar together for 2-3 minutes.
Add in the egg and vanilla and beat until well blended.
Add flour, quinoa flour, baking soda and salt and beat until no traces of flour remain.
Add in the chocolate chips and stir until they are well-distributed in the cookie dough.
Using a size 50 scoop, or a tablespoon, scoop out evenly sized cookie balls and place on a baking sheet approx. 2 inches apart. Repeat this process until the tray is full.
Press gently on the cookies to flatten the tops out slightly.
Bake in the oven for 10 to 12 minutes, or until cookies are golden brown.
Let the cookies cool on the baking sheet for a couple of minutes and then move them to a rack to cool completely before storing them in an airtight container.
Notes
The cookies will keep well in a covered container at room temperature for up to 5 days. They can be frozen for up to three months.