Heat oven to 350°F. In medium bowl, beat 1 cup butter, the granulated sugar and almond extract with electric mixer on medium speed until smooth. On low speed, beat in flour.
Shape dough into 1-inch balls; place 2 inches apart on ungreased cookie sheets.
Bake 12 to 15 minutes or until firm to the touch. Cool 1 minute; remove from cookie sheets to cooling racks. Cool completely, about 30 minutes.
In small bowl, beat powdered sugar, 2 tablespoons butter and the milk on medium speed until smooth and spreadable. Stir in green food color until uniform color.
Spoon frosting into resealable food-storage plastic bag. Seal bag; cut off tiny corner of bag. Squeeze bag to make tree shape in a zigzag pattern on each cookie with frosting.