Steps:

• Sift flour, cinnamon, salt, and baking soda together in a bowl.
• Beat butter and sugar with an electric mixer in a large bowl until smooth. Beat eggs, one at a time, into butter mixture until completely incorporated. Beat vanilla extract in with the last egg. Mix flour mixture into egg mixture until just incorporated. Fold in the chocolate chips, mixing dough just enough to evenly combine. Wrap dough in plastic and chill overnight.
• Preheat oven to 375 degrees F (190 degrees C).
• Roll cookie dough out on a lightly floured surface and cut into desired shapes with cookie cutters. Arrange cookies about 1 1/2 inch apart on baking sheets.
• Bake in the preheated oven until the edges are golden, 8 to 10 minutes. Allow the cookies to cool on the baking sheet for 5 minutes before removing to a wire rack to cool completely.

Steps:

• Sift (or whisk) the flour, cocoa powder, cream of tartar, baking soda and salt together then set aside. In a large bowl, using a handheld mixer on medium speed beat the butter, sugar and vanilla together until light and fluffy, 3 to 4 minutes. (Or, use a stand mixer fitted with the paddle attachment). Reduce speed to low. Add the eggs one at a time, beating well after each addition.
• Scrape the sides and bottom of the bowl then add the flour mixture in three parts, just mixing until it disappears. Stir in chocolate chips. Wrap with plastic wrap and chill dough at least 30 minutes or up to 3 days.
• Heat the oven to 400 degrees F. Line two baking sheets with parchment paper or use silicon baking mats.
• In a small bowl, mix the sugar and cinnamon together. Shape heaping-tablespoon-sized mounds of cookie dough into balls. Roll in the cinnamon-sugar mixture and place 2 inches apart onto baking sheets. (A medium cookie scoop is helpful here).
• Bake the cookies until the cookies have puffed a little and the tops look set, 8 to 10 minutes. Cool on baking sheets for 5 minutes then transfer to a cooling rack to cool completely. (The cookies will fall slightly as they cool.)