In a large bowl, cream together the sugar and shortening until light and fluffy.

Beat in the egg until well combined.

In a separate bowl, sift together the flour, cream of tartar, salt, and baking soda.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Cover the dough and chill in the refrigerator for at least 20 minutes.

Preheat oven to 375°F (190°C).

In a small bowl, mix together cinnamon and sugar for coating.

Remove the chilled dough from the refrigerator and roll into 1-inch balls.

Roll each ball in the cinnamon-sugar mixture.

Place the coated cookie dough balls onto ungreased baking sheets.

Bake for 8-10 minutes, or until edges are lightly golden.

Let cool on baking sheets for a few minutes before transferring to a wire rack to cool completely.