Butter Cookie Dough

• All-purpose (plain) flour, 3 cups (15 oz/470 g)
• Cake (soft-wheat) flour

Sift together the all-purpose and cake flours and the salt into a bowl. In a large bowl, using an electric mixer on low speed, beat the butter, sugar, and vanilla until smooth, about 1 minute. Add the flour mixture and mix just until a moist dough forms. Turn out the dough onto a lightly floured work surface. Divide into 3 equal portions, pat each into a flat disk, and wrap each in plastic wrap