Pecan Sandies: A melt-in-your-mouth Christmas tradition

This is part of Southern Kitchen's 12 Days of Cookies and Cocktails series, which runs daily through Christmas Eve. Each day, we'll pair fun festive cocktails with classic cookie recipes. These Pecan Sandies pair perfectly another classic: the Tom and Jerry. Get the recipe.
Food history:Pecans are a holiday staple. An enslaved gardener named Antoine paved the way
About the recipe
A staple of childhood Christmas cookie tins, the original Sandie is a melt-in-your-mouth shortbread cookie dotted with pecan pieces. You will have extra candied pecans, but — trust us — you'll be glad you do.
Makes: 7 dozen
Hands on time: 1 hour and 15 minutes
Total time: 3 hours and 10 minutes
Ingredients
Candied Pecans
1/4 cup egg whites
1 cup sugar
3/4 teaspoon salt
1/4 teaspoon pepper
3 cups pecans
Cookies
1 cup (2 sticks) unsalted butter, at room temperature
1/2 cup sugar
1/2 cup chopped candied pecans (above)
2 1/2 cups all-purpose flour
2 teaspoons vanilla
Instructions
To make the candied pecans: Heat the oven to 325 degrees.
In a large bowl, whisk the egg whites until frothy. Whisk in the sugar, salt and pepper until well-combined. Fold in the pecans to coat evenly in the egg white mixture. Spread the coated pecans in an even layer on an ungreased baking sheet.
Bake for exactly 8 minutes, stir the pecans, and then return to the oven. Continue to bake, stirring every 5 minutes, until the pecans are dry and there are no shiny spots left on the baking sheet, 10 to 15 minutes total. Let cool completely.
Measure out and chop 1/2 cup of the pecans to use in the cookies. Save the remainder for another use.
To make the cookies: In a stand mixer fitted with the paddle attachment or using a hand-held electric mixer, cream the butter and sugar until light and fluffy. On low speed, gradually beat in the flour, 1/2 cup at a time. Mix in the candied pecans and the vanilla.
Transfer the dough to a lightly floured counter and shape into two 1 1/2-inch-thick logs. Wrap with parchment paper and chill until firm, about 1 hour.
When ready to bake, return the oven to 325 degrees. Line two baking sheets with parchment paper.
Slice the dough into rounds about 1/4 inch thick and place on the prepared baking sheets about 1 inch apart. Bake until the tops are slightly browned, about 20 minutes. Let cool on the baking sheets for 5 minutes then transfer to a wire rack to cool completely. Repeat with the remaining dough. Serve.