In a large mixing bowl combine flour, cake flour, cornstarch, baking powder, salt and baking soda. Set aside.
2 cups all purpose flour, 1/2 cup cake flour, 1 tablespoon cornstarch, 1/2 teaspoon baking powder, 1/2 teaspoon salt, 1/2 teaspoon baking soda
In the bowl of a stand mixer fitted with a paddle attachment combine the butter, sugar and shortening. Beat on medium speed for 2 minutes, or until light and fluffy.
1 cup granulated sugar, 3 tablespoons granulated sugar, 1/2 cup salted butter, 3 tablespoons shortening
Add in eggs and mix until just combined.
1 egg, 1 egg yolk
Add in sour cream, vanilla and almond extract and mix until incorporated.
5 tablespoons sour cream, 1 teaspoon vanilla extract, 1/4 teaspoon almond extract
With the mixer running on low speed, slowly add in the flour mixture and mix until just combined. Be careful not to over-mix.
Remove the bowl from the stand mixer and cover it with plastic wrap. Place the bowl into the refrigerator to chill for 1 hour.
Towards the end of the chill time, preheat the oven to 375°F.
Line a baking sheet with parchment paper and lightly spray with baking spray. Set aside.
Once the dough is chilled, remove it from the fridge. Turn the dough out onto a clean, floured surface and roll out to 1/4-inch in thickness. Use a 3-inch round cookie cutter to cut as many cookies as you can. You may have to re-roll the dough a few times to use it all up.
Transfer the cut out cookies to the prepared baking sheet, spacing them out about 1-inch apart.
Place the baking sheet into the preheated oven on the center rack. Bake for 9 minutes, or until the edges are set and the centers are soft.
Once baked, remove from the oven and let the cookies rest on the baking sheet for a few minutes to allow them to set up a bit.
Once the cookies have set for a few minutes, transfer them to a wire cooling rack to let them completely cool. Repeat the baking process with the remaining cookies.