Preheat oven to 350°F (177°C). Lightly grease and line a 9 x 9-inch baking pan with parchment paper, leaving an inch or two overhangs on all sides for easy removal.
In a large bowl, whisk together the flours, cream of tartar, cinnamon, baking soda, salt, and baking powder until thoroughly combined.
In the bowl of a stand mixer fitted with the paddle attachment, beat together melted butter, the Redpath® Golden Yellow Sugar, and the Redpath® Granulated Sugar until well mixed and butter has completely cooled; 2 minutes.
Add the egg and incorporate it completely before adding the yolk and vanilla extract. Beat well after each addition.
Add half of the dry ingredients into the bowl, and mix on low speed until just combined. Repeat the process with the remaining dry ingredients until no flour streaks remain, and a dough is formed.
Transfer the dough to the prepared baking pan. Press and spread into an even layer.
Place into the fridge to chill and allow the flour to hydrate; at least 30 minutes.