Preheat your oven to 350°F and line a baking sheet with parchment paper. While the oven heats, measure out all your dry ingredients (flour, cream of tartar, baking soda, and salt) into a small bowl and whisk them together—this prevents lumps and ensures even distribution of the leavening agents. In a shallow bowl, combine the 2 tablespoons sugar with the ground cinnamon and set aside for coating. Having everything prepped and ready makes the dough-making process smooth and prevents overworking the dough.

In a mixing bowl, combine the softened butter, softened cream cheese, and 1/2 cup sugar. Beat for about 1 minute until the mixture is light and fluffy—this incorporates air and creates a tender cookie texture. The cream cheese adds a subtle tang and helps keep these small-batch cookies moist. Stop and scrape down the bowl as needed to ensure everything is evenly combined.

Add the large egg to the butter mixture and beat until fully combined, about 30 seconds. The egg acts as a binder and adds moisture to the dough. Make sure there are no streaks of egg white visible—everything should look uniform and pale.

Add the dry ingredient mixture from Step 1 to the wet ingredients. Mix on low speed or gently fold by hand until just combined—stop as soon as you don't see any streaks of flour. I prefer not to overmix at this stage because it can develop too much gluten and make the cookies tough rather than tender. The dough should come together easily but still be slightly crumbly at first, which is normal.

Using a small cookie scoop or spoon, portion the dough into balls about the size of walnuts. Roll each dough ball in the cinnamon-sugar coating from Step 1, making sure it's well covered on all sides. Space the coated dough balls about 2 inches apart on your prepared baking sheet—they'll spread slightly as they bake, but not dramatically.

Bake for 9 to 11 minutes, until the edges are just set but the centers still look slightly underdone—they'll continue to cook on the warm baking sheet. The cookies should look a bit soft when you remove them from the oven; this is the secret to keeping them chewy. Let them cool on the baking sheet for 1 minute, which allows them to firm up slightly without setting completely, then transfer them to a cooling rack to finish cooling. I find this short initial rest prevents them from falling apart when you move them.