Make 2 giant snickerdoodles in your air fryer with one bowl and 5 minutes of prep. This small-batch recipe creates soft, gooey cookies with crispy cinnamon-sugar edges without heating up your oven.
Place the butter in a medium sized mixing bowl. Microwave to melt the butter.
Add 3 tablespoons of sugar, egg yolk, and vanilla to the melted butter and stir well with a fork to combine.
Once combined, stir in the flour, cornstarch, cream of tartar, baking soda, and salt until well combined and smooth.
Form the cookie dough into 2 balls.
Preheat air fryer to 350 degrees.
Add the remaining 2 teaspoons of sugar and cinnamon to a plate and stir to combine. Roll the cookie dough through the cinnamon sugar to coat.
Flatten the cookie dough lightly and place the balls on a sheet of air fryer parchment paper a couple of inches apart. Place in your preheated air fryer. Air fry for 5 minutes.
Remove the basket from the air fryer, but leave the cookie in the basket. Let cool for at least 20 minutes before handling or the cookie will fall apart. The longer it cools, the more firm it will become.
Notes
This cookie is gooey on the inside and perfectly cooked on the outside. It’s meant to be this way. If you don’t like underbaked, gooey cookies this probably isn’t the one for you. If you want a more done cookie, you can up the bake time (but the outside will brown a bit more) and you can let it cool longer to really firm up. We like it gooey and eat it pretty quickly after just a 20 minute cooling time. If your parchment paper curls up a bit and misshapes the cookies as they bake (or the cookies bake into each other), take a small bowl or large glass that’s just a bit wider than a single cookie and place it directly over a cookie immediately after removing the air fryer basket from the air fryer. Swirl the bowl around a bit in a circle to reshape the cookie into a perfect circle. Makes it look bakery perfect!