The New Classic Snickerdoodle Cookie

Steps

1. In a small bowl, combine the flour, brown sugar, cinnamon, and salt. Add the softened butter and use your fingers to rub the mixture together until it forms small, moist clumps. I like to mix until the butter is thoroughly combined and no butter bits are visible.
2. Use your fingers to break the streusel into small bits and spread in a thin, even layer on a small plate or sheet pan and place in the freezer while you make the cookie dough. This helps it firm up so it adheres to the dough without melting into it.
3. Whisk the dry ingredients: In a medium bowl, whisk together the flour, baking powder, baking soda, salt, cornstarch, cream of tartar, and cinnamon. Set aside.
4. Mix the butter and sugars: In the bowl of a stand mixer fitted with a paddle attachment, combine the cold butter cubes, brown sugar, and granulated sugar.
5. Mix on medium-low speed until the butter breaks down and the mixture comes together into a cohesive, slightly crumbly dough. This will take 2 to 3 minutes.  Don’t rush it, but also don’t let it get fluffy. We’re not creaming we’re just mixing until combined.
6. Add the egg, egg yolks, and vanilla extract. Mix on low speed until fully incorporated, scraping down the sides of the bowl as needed. The dough will look glossy and thick.
7. Add the dry ingredients all at once and mix on low speed until just combined. The dough will be thick, soft, and slightly tacky.
8. Chill the dough: Scoop the dough into large portions.  I like about 4 to 5 ounces each (yes, we’re going big here) and roll into rough balls that are taller than they are wide.
9. Refrigerate the dough balls for at least 2 hours, or freeze for 30–45 minutes, until firm. This step is what gives us that tall, bakery-style cookie.
10. Roll in cinnamon sugar: In a small bowl, stir together the sugar, cinnamon, and a pinch of salt. Roll each chilled dough ball generously into the streusel topping you’ve removed from the freezer, and then in the cinnamon sugar mixture, really pressing it on so you get that crackly, sparkly exterior.
11. Bake: Place the cookies on a parchment-lined baking sheet, spacing them well apart (these are big cookies with opinions). Bake in a 350°F oven for 14–16 minutes, until the edges are set, the tops are crackled, and the centers still look slightly underbaked.
12. For extra height, you can gently reshape the cookies with a round cutter or glass right after baking—but honestly, they tend to behave themselves.
13. Cool (just a little): Let the cookies rest on the baking sheet for 10 minutes before moving to a wire rack.