1. Preheat oven to 400 degrees F (200 degrees C).
2. Cream together butter, shortening, sugar, egg and the vanilla.
3. In a separate bowl, blend in the flour, cream of tartar, soda and salt.
4. Now add the dry into the wet ingredients and blend well.
5. Make sure you don`t overmix them. The result will be a slightly sticky dough.
6. Mix the cinnamon, cardamom (if using) along with sugar and spread it on a plate.
7. Shape dough by rounded spoonfuls into balls. Since the dough is little sticky, I actually dusted my hands with the sugar and spice mixture to help me shape the rounds.
8. You anyways have to coat them with this mixture and I thought why not use it to make rounds too.
9. It worked pretty well for me.
10. Once shaped, roll the balls of dough in the sugar+spice mixture until well coated on all sides.
11. Make sure to place these balls at least 2 inches apart on an ungreased baking sheet (or use parchment paper).
12. They spread while baking.
13. Depending on the size, you get about 22-24 cookies with this recipe.
14. By removing them after 5-6 minutes, they are crisp on the surface and break well – but the insides are slightly soft.

Courtesy: http://chefinyou.com/