Prepare the oven. Adjust oven rack to middle position and preheat to 350°F (176°C).
Cream the butter and sugar. Using the bowl of your stand mixer, cream the butter and sugar until pale, ivory, and fluffy for about 5 minutes.
Add the egg, vanilla, almond extract. While the mixer is mixing, add the egg, vanilla, and almond extract until combined. Scrape down the edges of the bowl to evenly mix.
Whisk the remaining dry ingredients and add to butter. In a large mixing bowl, whisk together the cake flour, baking powder, baking soda, cream of tartar, cornstarch, and salt until combined. Lower the mixer speed to low and slowly add in the dry ingredients until just combined. Do not over mix. Finish mixing the dough with a rubber spatula to make sure all the flour is thoroughly combined.
Scoop onto a lined sheet pan. Using a 2-tablespoon cookie scoop, scoop the dough into 24 balls onto a slipmat or double parchment-lined half sheet pan. Cover with plastic wrap and chill in the refrigerator for 2 hours.
Bake at 350°F (176°C). Roll out the balls and slightly flatten with your palm into 1/2 inch thick cookies (this will allow the cookies to cook evenly without a hump in the center). Place them on the lined sheet pan about 2 inches away from each other. Bake for about 10-11 minutes or until puffed and pale. The cookies may look slightly underdone in the center. Leave the cookies to cool on sheet pans until completely cooled, about an additional 15 minutes.