Citrusy Shortbread Cookies

Adapted from a recipe found at www.familycircle.com

I first tried this one last summer, and it was a hit with our family. I made only half with dried fruit and nuts since two of my boys don’t care for those extras.
Ingredients
1 1/2  C. (3 sticks) unsalted butter, softened
1 1/2  C. plus 2 tables. sugar
2  egg yolks
2  tables. almond extract
1  teas. each orange and lemon zest
3  C. flour
1/4  teas. salt
1  beaten egg white
Chopped nuts or dried fruit (optional)
Directions
1. Heat oven to 325°F. Line a 17 x 12 x 1-inch baking pan with nonstick foil. In large bowl, cream together butter and 1 1/2 cups of the sugar.
2. Slowly add egg yolks, and beat well until smooth. Beat in almond extract and zest.
3. Stir in flour and salt until combined.
4. Spread dough evenly into prepared pan, flattening as smoothly as possible.
5. Brush top of dough with egg white; sprinkle with nuts or fruit (if using) and with remaining 2 tablespoons sugar.
6. Bake at 325°F for 25 minutes or until brown, turn off oven and allow cookies to sit in oven (with door ajar) for 15 minutes. Cut while slightly warm.
(Tip: I used dried cherry-flavored cranberries, chopped, and walnuts when I tried this delicious recipe. Chopped pistachios added would make a Christmasy combination. Also, I pressed the fruit and nuts into the dough slightly.)