Jell-O Cookies

1 cup butter
1-1/2 cup powdered sugar
1 large package jell-o
1 teaspoon vanilla
2-1/2 cups flour
1 egg
1 teapsoon baking powder
1 teaspoon cream of tartar

Mix ingredients. Refrigerate at least 3 hours. Roll out on floured cloth to 1/8". Cut out circles. Place on greased cookie sheet at least 1" apart. Bake at 375F for 10 minutes.