Season flour with cardamom and salt. Whisk for 30 seconds to combine.
Add margarine and icing sugar to mixer and mix until well incorporated. Scrape down the sides of the bowl and combine thoroughly.
Add flour mixture and mix on low speed until well blended. The mixture will be crumbled and soft.
Wrap dough and refrigerate for 1- 2 hrs. Preheat oven to 325 F. Unwrap and place between two pieces of parchment paper and roll to 1/4-inch thickness. Trim your edges and use a ruler to mark equal rectangular shapes into dough. Careful not to let your making cut through the dough fully.
Bake for 10- 15 minutes or until lightly golden brown. Remove from oven and let cool slightly before using a sharp object to divide into rectangular shapes.
Combine sugar and Indi Ground Cinnamon. Roll fully cooled cookie to coat. Enjoy.