1. Place flour, sugar, salt, 1 tsp cinnamon, butter and orange zest in the bowl fitted with the kneading/crushing blade. Mix at speed 8 for 3 minutes. Using a spatula, bring the mixture to the center and mix again for 20-30 seconds.
2. Form dough into a ball and wrap in plastic wrap. Refrigerate for 30 minutes.
3. Preheat the oven to 350°F.
4. Stir together the 1 1/2 tsp cinnamon and 4 Tbsp sugar in a small bowl. Form the dough into 1 Tbsp. size balls. Roll the balls in cinnamon sugar mixture and place 2 1/2 inches apart on a cookie sheet lined with parchment paper. Flatten slightly with the bottom of a glass dipped in sugar mixture.
5. Bake for 11-13 minutes or until light brown. Cookies should be soft at the end of baking; they will crisp up as they cool.