Place 1 cup room temperature butter in the bowl of a stand mixer fitted with the paddle attachment. Add 1½ cups white granulated sugar. Start on low speed until butter breaks up and combines with sugar, forming larger clumps. Scrape down the sides, increase to speed two until more combined, then increase to medium-high speed to whip air into the mixture until lighter and fluffier.

Crack eggs into a separate small bowl first to check for shells. Add one egg at a time to the butter mixture, mixing on low speed until incorporated before adding the next. After the second egg, add 1 teaspoon vanilla extract and mix briefly. Scrape down the sides of the bowl.

In a medium bowl, combine 2¾ cups all-purpose flour, ¼ teaspoon salt, 2 teaspoons cream of tartar, and 1 teaspoon baking soda. Whisk or stir together to evenly disperse the dry ingredients.

Add the dry ingredients to the wet ingredients about one-third at a time. Mix on low speed just until flour is no longer visible in the dough. Scrape down the sides between additions. Do not overmix.

Transfer cookie dough to a bowl, cover with plastic wrap, and refrigerate for 30 minutes. While the dough chills, preheat your oven to 375℉/190℃. Make sure your oven rack is positioned in the center.

In a small bowl, combine ¼ cup white granulated sugar with 4 teaspoons ground cinnamon. Mix well and set aside.

Using a 1-tablespoon cookie scoop or measuring spoon, portion out the dough. Roll each portion lightly in your hands to form a ball, then roll in the cinnamon-sugar mixture until evenly coated. Place on light-colored baking sheets, spacing about 2 inches apart.

Bake at 375℉/190℃ for 8-10 minutes. Cookies are done when edges are set but centers are still very soft. Do not open the oven door until at least 6 minutes into baking.

Let cookies cool on the baking sheet for 1-2 minutes. While still warm, sprinkle a little extra cinnamon sugar on top of each cookie. Use a thin spatula to transfer cookies to a wire rack to cool completely before storing.