- 1 large egg
- 1/2 cup unsalted butter (1 stick)
- 3/4 cup light brown sugar, packed
- 1/4 cup granulated sugar
- 1 tablespoon Greek yogurt or sour cream
- 1 tablespoon vanilla extract
- 1 1/2 cups all-purpose flour
- 2 teaspoons cinnamon
- 2 teaspoons cornstarch
- 1 teaspoon cream of tartar
- 1/2 teaspoon baking soda
- pinch salt, optional and to taste
- one 10-ounce bag (about 1 2/3 cups) cinnamon chips
To the bowl of a stand mixer fitted with the paddle attachment, combine the egg, butter, sugars, and beat on medium-high speed until well-creamed, light and fluffy, about 5 minutes (or use a hand mixer and beat for at least 7 minutes).
Add the Greek yogurt, vanilla, and beat to incorporate until fluffy again, about 2 minutes.
Stop, scrape down the sides of the bowl, and add the flour, cinnamon, cornstarch, cream of tartar, baking soda, optional salt, and beat until just incorporated, about 2 minutes. Don’t overmix.
Add the cinnamon chips and either fold in by hand or beat momentarily to combine.
Preheat oven to 350F, line a baking sheet with a Silpat, parchment, or spray with cooking spray. Place mounds on baking sheet, spaced at least 2 inches apart (I bake 8 cookies per sheet). Bake for 8 to 9 minutes, or until edges have set and tops are just beginning to set, even if slightly undercooked, pale and glossy in the center. Do not bake longer than 10 minutes as cookies will firm up as they cool (The cookies shown in the photos were baked with dough that had been chilled overnight, allowed to come to room temp for 15 minutes, and were baked for 8 minutes, with trays rotated at the 4-minute mark. They have chewy edges with soft, pillowy centers). Allow cookies to cool on the baking sheet for 5 minutes before removing and transferring to a rack to finish cooling.
Store cookies airtight at room temperature for up to 1 week, or in the freezer for up to 3 months. Alternatively, unbaked cookie dough can be stored airtight in the refrigerator for up to 5 days, so consider baking only as many cookies as desired and save the remaining dough to be baked in the future when desired.