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.
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.
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)
Bake for 7-10 minutes, or until no longer "wet" looking in the center. These cookies are best when slightly under-done.