Preheat oven to 410° degrees F. Line 2 baking sheets with parchment paper or silicone liners; set aside.
In the bowl of a stand mixer, cream together the butter, brown sugar, and granulated sugar on low speed for 30 seconds. Increase speed to medium and beat for another 30 seconds. Lastly, increase speed to high and beat for 30 seconds, scraping down the sides of the bowl as needed, until mixture is light and fluffy.
Add in the eggs, one at a time, beating well after each addition, followed by the vanilla, if using. Add in the cake flour, oats, all-purpose flour, cornstarch, baking soda, salt, and cinnamon and mix on low speed until incorporated. Lastly, stir in the raisins.
Refrigerate the dough briefly for 15 minutes.
Using your hands, weigh out 6 ounces of cookie dough and barely form into a very rough ball shape. Place in a staggered pattern, 3" apart on the baking sheet with only 4 cookies to a baking sheet. Bake one sheet at a time in the middle rack of the oven for 9-12 minutes or until the cookies appear dull and light golden brown on top; do not over-bake. Cookies will continue to finish cooking as they set and cool on the baking sheets. Allow cookies to set on the baking sheets for at least 30 minutes before moving as cookies are quite delicate after baking.