- In the bowl of a stand mixer with paddle attachment, blend sugar, butter, egg, and vanilla on low to just combine. Switch mixer to medium-high and mixer for about 3 minutes, or until light a fluffy. 
- While that is mixer place flour, cake flour, cornstarch, baking powder and baking soda into a bowl and whisk together. 
- With the mixer on low speed, slowly add dry ingredients into the butter mixture. Mix until just combined. 
- Remove bowl from mixer and add in pinch of salt. With a rubber spatula, scrape down sides of bowl and gently mix ingredients. 
- Using a small ice cream scoop, scoop out balls of sugar cookie and place on a parchment lined baking sheet close together. 
- Do this until all the dough is gone; you should have about 24 sugar cookie dough balls. 
- Place in freezer for at least one hour. (if freezing for longer make sure the sugar cookie dough is sealed in an air tight container until ready to use) 
- When ready to bake heat oven to 350°F. (325 in convection ovens) 
- Place dough ball (can still be frozen) on parchment lined baking sheet 2 inches apart from each other. 
- Bake for 7-10 minutes, or until no longer "wet" looking in the center. These cookies are best when slightly under-done.