1½ sticks (¾ cup) unsalted butter, softened to room temperature
½ cup sugar
½ teaspoon vanilla extract
½ teaspoon salt
3 egg yolks, room temperature
1 up all-purpose flour
½ cup whole wheat all-purpose flour
In a stand mixer with a paddle attachment, cream together butter, sugar, vanilla and salt until light and fluffy. Add in egg yolks one at a time making sure each yolk gets thoroughly blended into the sugar mixture before adding the next yolk.
Carefully add in the flours and mix at low then medium speed until dough ball forms and most of the dough has combined into the ball. Stop the mixer, hand blend any remaining dough that might be sticking to the sides of the mixing bowl by either using a wooden spoon, or scraping the extra off with a rubber scraper.
Form the dough into a smooth, even dough ball. Cut the dough ball in half, and take the halves and press each half into a round disk on some waxed paper. The disk should be about ¾ inches thick. Once you have created a dough dish, wrap each disk up in the wax paper, and refrigerate on a plate until firm, at least 2 hours or so.
When ready to bake the sugar cookies, remove dough from the refrigerator and heat the oven to 350 degrees. Roll dough out once soft enough to roll, but not too soft (too soft would be similar feel to when you initially formed the dough out of the mixer). Roll out dough to desired thickness (¼ inch is best for decorating.) If you will not be using the dough for decorating, then you can roll the dough out thinner if you like. Cut out cookies in the cookie cutter shapes you like and transfer to a baking sheet. Bake about 15 minutes if using dough that is about ¼-inch thick. (Less time may be needed for thinner cookies). The cookies are done once they have turned a nice golden yellow, and some hints of golden brown on the edges and/or bottom of cookies. Remove from oven and allow to cool thoroughly before decorating. These cookies will be good to enjoy for up to 2 weeks -- if they even last in your house that long!
Makes 1 dozen cookies.