3 cups (375g) all-purpose flour (spoon & leveled)
\n2 teaspoons cream of tartar*
\n1 teaspoon baking soda
\n1 and 1\/2 teaspoons ground cinnamon
\n1\/2 teaspoon salt
\n1 cup (2 sticks or 230g) unsalted butter, softened to room temperature
\n1 and 1\/3 cup (267g) granulated sugar
\n1 large egg + 1 large egg yolk, at room temperature
\n2 teaspoons pure vanilla extract<\/p>\n
1\/3 cup (70g) granulated sugar
\n1 teaspoon ground cinnamon
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\nPreheat oven to 375\u00b0F (190\u00b0C). Line two large cookie sheets with parchment paper or silicone baking mats (always recommended for cookies). Set aside.<\/p>\n
Make the topping: Combine the granulated sugar and cinnamon together in a small bowl.<\/p>\n
Make the cookies: Whisk together the flour, cream of tartar, baking soda, cinnamon, and salt together in a medium bowl.<\/p>\n
In a large bowl using a hand mixer or stand mixer fitted with a paddle attachment, beat the butter and granulated sugar together on high speed until smooth and creamy, about 2 minutes. Add the egg, egg yolk, and vanilla extract. Beat on medium-high speed until combined. Scrape down the sides and up the bottom of the bowl with a rubber spatula as needed. With the mixer running on low speed, slowly add the dry ingredients to the wet ingredients in 3 different parts. The dough will be thick.<\/p>\n
Roll cookie dough into balls, about 1.5 Tablespoons of cookie dough each. I recommend this cookie scoop. Roll the dough balls in cinnamon-sugar topping. Sprinkle extra cinnamon-sugar on top if desired. Arrange 3 inches apart on the baking sheets.<\/p>\n
Bake cookies for 10 minutes. The cookies will be very puffy and soft. When they are still very warm, lightly press down on them with the back of a spoon or fork to help flatten them out. Allow cookies to cool on the baking sheet for 10 minutes and transfer to a wire rack to cool completely.<\/p>\n