Eggnog Thumbprint Cookies

Contributed by Catsrecipes Y-Group
 * Source: SeasonsAtHome
 * Makes about 40 cookies

Ingredients

 * ⅔ cup butter, softened
 * ½ cup granulated sugar
 * ⅛ teaspoon ground nutmeg
 * 2 egg yolks
 * 1 teaspoon vanilla
 * 1½ cups all-purpose flour
 * 2 slightly beaten egg whites
 * 1 cup finely chopped walnuts
 * ¼ cup butter
 * 1 cup sifted powdered sugar
 * 1 teaspoon rum or ¼ teaspoon rum extract
 * 1 to 2 teaspoons milk
 * ground nutmeg

Directions

 * 1) Beat the ⅔-cup butter in a mixing bowl with an electric mixer on medium to high speed for 30 seconds.
 * 2) Add granulated sugar and the ⅛-teaspoon nutmeg; beat until combined.
 * 3) Beat in egg yolks and vanilla.
 * 4) Beat in as much flour as you can.
 * 5) Stir in any remaining flour with a wooden spoon.
 * 6) If necessary, cover and chill dough about 1 hour or until easy to handle.
 * 7) Shape into 1-inch balls.
 * 8) Roll balls in egg whites, then in chopped walnuts.
 * 9) Place 1 inch apart on lightly greased cookie sheets.
 * 10) Press centers with your thumb.
 * 11) Bake in a 375°F oven for 10 to 12 minutes or until edges are lightly browned.
 * 12) Cool on wire racks.
 * 13) For filling, beat the ¼-cup butter until softened.
 * 14) Add powdered sugar and beat until fluffy.
 * 15) Beat in rum or rum extract and enough milk to make of spreading consistency.
 * 16) Spoon or pipe about ½ teaspoon filling into center of each cookie.
 * 17) Sprinkle with nutmeg.