Preheat the oven to 375°F. Line 2 baking sheets with parchment paper.
In a large bowl, beat together 1½ cups sugar, butter, vanilla and salt with an electric mixer until light and fluffy. Add eggs one at a time, mixing after each egg.
In a medium bowl, mix together flour, cream of tartar, baking soda, cocoa powder, ½ teaspoon cinnamon, and cayenne pepper. Add to wet ingredients and beat to combine. Fold in chocolate chips.
In a small bowl, combine remaining ¼ cup sugar and ½ teaspoon of cinnamon.
Scoop dough balls with a cookie scoop and roll into balls. Roll in cinnamon sugar mixture, then place on prepared baking sheets.
Bake for 10 - 12 minutes or until edges are slightly cracked. Let cool for 5 minutes before removing to a wire rack to cool.