Susan's French Buttercream Cookies

Susan makes these every year for Christmas. An excellent shortbread type cookie.

1 1/2 cup confectioner's sugar
1 tsp. baking soda
1 tsp. cream of tartar
1/4 tsp. salt
1 cup margarine
1 egg
1 tsp. vanilla
2 1/4 cup flour
Colored sugar for sprinkling on top

Mix all but the flour and the colored sugar for 1 minute with an electric mixer. Add the flour.

Chill 30 minutes. Shape into 3/4" balls and place on greased cookie sheets. [Cookies will puff up and spread a bit so leave a little space between the cookies.] Flatten with a fork in criss-cross fashion. Sprinkle with colored sugar.

Bake at 350° F. for 5 - 8 minutes until set but not brown. [Mine took about 10 minutes.]

Makes 4 dozen [I get about 36 using my cookie scoop and leveling the dough to the top of the scoop. They could be smaller for a Christmas cookie.]