Preheat the oven to 350 degrees F. Line baking sheets with parchment paper or silpat mats.
In a medium bowl, sift together the flour, cream of tartar, baking soda and salt. In a separate, small bowl, stir together ½ cup of sugar and the cinnamon; set both bowls aside.
In a large bowl, use an electric mixer to beat the butter and remaining 1½ cups sugar until blended together, about 1 minute. Add the eggs and vanilla extract; mix until blended, about 1 minute. Add the flour mixture and mix just until incorporated. Stir in the chocolate chips and toffee pieces.
Scoop out a heaping tablespoonful of dough and use your hands to roll it into a ball. Roll in the cinnamon-sugar mixture. Repeat with remaining dough. Place cookies 3 inches apart on the cookie sheets (I baked 8 at a time and found that was perfect).
Bake the cookies until the edges are golden, centers are still golden and no longer look raw in the middle, about 16 minutes. Cool the cookies on a baking sheet for at least 5 minutes, then remove to a rack to cool completely.
Notes
If you don't have access to Heath candy bars you can always use packaged toffee bits or some other kind of toffee candy bar.