1 1/2 c. powdered sugar
1 tsp. baking soda
1 tsp. cream of tartar
1/4 tsp. salt
1 c. softened butter
1 egg
1 tsp. vanilla
2 1/4 c. all-purpose flour

In large bowl, combine all ingredients, except flour, on low speed of mixer about 1 minute. Blend well. Gradually add the flour. Blend at low speed of mixer. If desired, tint dough with a few drops of food coloring. Chill dough 15 to 30 minutes. Shape dough into 3/4 inch balls, place on greased cookie sheet about 2 inches apart. Flatten balls with fork; sprinkle with colored sugar. Bake at 350 degrees for 5 to 8 minutes until set, not brown. Let cookies stand on cookie sheet about 1 minute. Cool on racks. Makes 4 dozen cookies.