1. Line a baking sheet with heavy-duty foil and spray with vegetable cooking spray.
2. Prepare the caramel crunch. In a large, heavy skillet heat 1 cup of the sugar over medium heat, stirring occasionally with a wooden spoon to help it melt evenly. When the sugar is melted, lower heat to medium-low and cook to a golden color, about 3 to 6 minutes. Immediately pour the caramelized sugar carefully onto the prepared baking sheet. Tilt the sheet so that sugar spreads to a thickness of no more than 1/8 inch. Allow to cool until hard and cool to the touch, about 30 minutes.
3. Break the caramel into several pieces, then place on a cutting board and use a knife to chop into 1/4- to 1/2-inch pieces. (The caramel can be stored in a tightly sealed container for up to 3 days at room temperature.)
4. Preheat the oven to 325degreesF. Line 2 baking sheets with parchment paper, or spray with vegetable cooking spray. In a small bowl, stir 1/2 cup of the sugar together with the cinnamon. Set aside.
5. Make the cookies. In a medium bowl, sift together flour, cream of tartar, baking soda, and salt. Set aside. In a large bowl, use an electric mixer on medium speed to beat the butter and remaining 11/2 cups sugar until smooth, about 1 minute. Mix in the eggs and vanilla until blended. On low speed, mix in the flour mixture until it is incorporated. Stir in the chopped caramel pieces.The dough will be stiff.
6. Scoop out a well-rounded tablespoon of dough and roll between your palms into a smooth ball. Roll ball in the cinnamon sugar mix. Repeat with remaining dough and place balls 3 inches apart on the baking sheets. (You will not use all the cinnamon sugar, but a large quantity is easier to work with.)
7. Bake cookies, one sheet at a time, just until the edges are golden but the centers are pale and feel soft if lightly touched, about 15 to 18 minutes. Cool the cookies for 5 minutes on the baking sheets, then transfer to a wire rack to cool. Serve or store in a tightly covered container for up to 3 days, or freeze.
Source: Fresh Magazine September, October 2010