Preheat oven to 350 degrees and line 2 cookie sheets with parchment paper

Using a large bowl, beat together the butter, brown sugar, and sugar until combined and creamy

Beat in the eggs, 1 at a time until combined

Beat in the vanilla

Using another large bowl, whisk together the flour, cocoa powder, cream of tartar, baking soda, baking powder, and salt until combined

Gradually mix in the dry ingredients into the wet ingredients until combined and a dough forms

Using a small bowl, whisk together the 1 C of sugar and 1 tsp of cinnamon

Using a small ice cream scooper, scoop out about 1 ½ tbsp of cookie dough

Roll into a ball in your hands

Coat cookie dough ball in the cinnamon-sugar mixture

Place onto a cookie tray

Place into the oven and bake for 10-12 minutes or until the edges are set and the middle looks soft

Allow cooling completely before enjoying