Melt the butter in a small saucepan over medium heat, stirring occasionally until it starts to turn golden brown and smell nutty, about 5-7 minutes. Immediately remove the pan from the heat and pour the butter into a large heatproof bowl. 

Add the brown sugar and ¼ cup granulated sugar to the melted brown butter and whisk to combine. 

Next add the egg and vanilla extract. Mix to combine. 

In a separate bowl, whisk together the flour, 1/2 teaspoon of cinnamon, baking powder, cream of tartar, baking soda, salt, and nutmeg.

Add the dry ingredients to the wet ingredients and just until incorporated and no large lumps of flour remain. 

Cover the cookie dough and transfer it to the fridge to chill for 1 hour. 

Preheat the oven to 350°F and line two large baking sheets with parchment paper.

In a small bowl, mix together the remaining 1/4 cup of granulated sugar and 1/2 teaspoon of cinnamon.

Scoop out 2-tablespoon sized portions of cookie dough and roll them into smooth balls. 

Roll each ball in the cinnamon sugar mixture, making sure it's evenly coated on all sides.

Place the cookie dough balls on the prepared baking sheet, making sure to leave at least 2” of space between each once. Press the dough balls down into a ⅓” tall disc. 

Bake the cookies for 12-15 minutes, or until the edges are golden brown and the center is set. For chewy snickerdoodles, I recommend 12 minutes. For crunchy snickerdoodles, bake the cookies for 15 minutes. 

Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely. Enjoy.