Step 1

Preheat the oven to 400°F. Position racks in the upper and lower thirds of the oven. Line two baking sheets with parchment paper.

Step 2

In a medium bowl, whisk together the flour, cream of tartar, baking soda and salt. Set aside.

Step 3

In the bowl of an electric mixer, beat the butter with 1-1/2 cups of the sugar until smooth and creamy, 1 to 2 minutes. Add the eggs and beat until combined. Add the flour mixture and mix on low speed until the dough comes together. Using your hands, gather the dough into a ball and wrap in plastic wrap (dust your hands with flour if the dough is sticky); refrigerate until firm, at least 30 minutes.

Step 4

In a small bowl, mix together the remaining two tablespoons of sugar and the cinnamon. Pinch off tablespoons of dough and shape into 1-inch balls. Roll the balls in the cinnamon-sugar and place on the prepared baking sheets about 2 inches apart. Bake for 8 to 9 minutes, shifting the cookie sheets from top to bottom and front to back halfway through baking. Let the cookies cool on the baking sheets for a few minutes, then transfer to a wire rack to cool completely. Store in an airtight container.

Step 5

Note: These cookies are best enjoyed fresh on the day they are made. However, the cookies can be reheated briefly in the microwave for that fresh out of the oven texture. The dough may also be stored in the refrigerator for several days.

Step 6

Freezer-Friendly Instructions: The cookie dough can be frozen for up to 3 months: Roll the dough into balls, let set on a baking sheet in the freezer, then place in a sealable bag and press out as much air as possible. Bake as needed directly from the freezer. (Allow 1 to 2 minutes longer in the oven.) The baked cookies can also be frozen for up to 3 months. Let the cookies cool completely and store in an airtight container separating layers with parchment paper or aluminum foil. Before serving, remove the cookies from the container and let them come to room temperature.