- 2 cups (254 grams) all-purpose flour
- 1 teaspoon cream of tartar
- 1/4 teaspoon baking soda
- 1/4 teaspoon salt
- 1 stick (114 grams) unsalted butter, at cool room temperature
- 1/2 cup (134 grams) smooth peanut butter
- 3/4 cup (148 grams) granulated sugar, divided
- 1/4 cup (50 grams) packed dark brown sugar
- 1 large egg
- 1 teaspoon vanilla extract
- 1 teaspoon ground cinnamon
Preheat the oven to 350°F. Line large baking sheets with parchment paper or silicone baking mats.
In a medium bowl, combine the flour, cream of tartar, baking soda, and salt.
In the bowl of an electric mixer, beat the butter, peanut butter, 1/2 cup granulated sugar, and the brown sugar on medium-high speed until well combined and smooth, about 3 minutes. Add the egg and vanilla and beat until combined. On low speed, gradually add the flour mixture and beat until incorporated.
Place the remaining 1/4 cup of sugar with the cinnamon in a shallow dish. Using a medium, spring-loaded cookie scoop, shape the dough into 1 1/2 tablespoon rounds then roll in sugar to coat evenly. Place the dough balls on the prepared baking sheets and flatten with the bottom of a measuring cup or glass.
Bake for 10 to 12 minutes, or until the cookies are set and begin to brown. Let the cookies cool for 5 minutes before removing to a wire rack to cool completely.