Preheat the oven to 400°F.
Whisk together the All-purpose flour, cake flour, cornstarch, baking soda, baking powder, and salt together in a large bowl. Set aside.
2 1/2 cups All-Purpose Flour, 1 1/2 cups Cake Flour, 2 tsp. corn starch, 1 tsp. baking soda, 1 tsp. baking powder, 1 tsp. salt
Place the butter into the bowl of a stand mixer and secure the paddle attachement. Turn the mixer on the lowest setting. Let the mixer cream the butter for ~30 seconds, followed by the white sugar until light and fluffy. 2-4 minutes.
1 cup unsalted butter, cold, cubed (16 Tbsp.), 1 1/4 cups sugar
Then add in the eggs, egg yolks, extracts, lemon juice, lemon zest and food coloring. Blend until mixed. If any of the butter gets stuck on the paddle attachment use a rubber spatula to knock it off.
2 large eggs, 2 large egg yolks, 3/4 tsp. vanilla extract, 3/4 tsp. lemon extract, 1/4 cup fresh lemon juice (4 Tbsp.), 2 tsp. lemon zest (add more for more lemon flavor!), 2-5 drops yellow food coloring (optional)
Gradually add in the flour mixture. Mix until combined. Turn machine off.
Measure out ~8, 5 oz. cookies (you can of course make smaller if you want!). In a bowl or shallow dish, roll the dough balls in granulated sugar first, and then in powdered sugar next. Place 6 cookies on 1 cookie sheet and 2 on another.
1/2 cup granulated sugar, 1/2 cup powdered sugar
Bake cookies for 11-13 minutes. Let them rest on the cookie sheet for 15 minutes and then transfer them to a cooling rack. Enjoy!