In large bowl, beat ¾ cup butter and ½ cup sugar with electric mixer on medium speed until light and fluffy.

Add egg; beat well.

Stir in 1¾ cups flour, the baking soda, cream of tartar and salt.

Knead dough into smooth ball.

Wrap in plastic wrap; refrigerate until firm, about 1 hour.

Meanwhile, in small bowl, mix ½ cup butter, the milk and ½ cup flour with fork until well mixed.

Divide mixture in half.

Stir red food color into one half and green food color into other half.

Spoon each mixture into separate decorating bag fitted with small writing tip; set aside.

Heat oven to 375°F.

Shape cookie dough into ¾-inch balls.

On ungreased cookie sheets, place balls 2 inches apart.

In small bowl, place 2 tablespoons sugar.

Dip bottom of glass into sugar and flatten each ball into 1½-inch round.

Pipe colored mixture from decorating bags onto each cookie in holiday designs.

Bake 7 to 9 minutes or until set.

Immediately remove from cookie sheets to cooling racks.