In a small saucepan over medium heat, melt the butter. Continue cooking, until the butter foams and then darkens in color slightly and is very fragrant, 3 to 4 minutes. Transfer the butter immediately to a heatproof bowl, and let it cool at room temperature for 20 minutes.

Heat the oven to 350ºF. Line a sheet pan with parchment paper. As the butter is cooling, combine the flour, cream of tartar, baking soda, salt, 1 cup (200 g) of the sugar, and the brown sugar in a large bowl.

Add the cooled brown butter, the beaten eggs, the vanilla, and bourbon. Stir with a spatula until you have a cohesive dough.

In a small bowl, combine the remaining ¼ cup (50 g) sugar and the cinnamon.

Using a medium 1.75-inch (#40) scoop (which is about 2 tablespoons) portion the dough into balls. Note: I use a digital scale and portion the dough into 50 gram balls — not necessary, but I love knowing the balls all weigh the same and so in turn will bake the same.

Roll the dough balls in the cinnamon and sugar and transfer 8 to the prepared sheet pan. (NOTE: Some commenters have had trouble with the cookies spreading. If you are worried about spreading, consider chilling the portioned dough balls for 1 to 3 hours or even longer before baking. I often portion cookie dough balls, transfer them to an airtight container, and chill for 24 hours.) Bake for 8 to 11 minutes — dough balls will puff up and they will look not completely cooked, but you should remove them anyway — they’ll collapse and continue to cook as they cool. I do find that overcooking snickerdoodles renders them more light and cake-like and less chewy. Remove the pan from the oven. Let the cookies cool slightly on the baking sheets; then transfer to a wire rack to cool completely.

Repeat with the other dough balls or transfer them to an airtight container and store in the fridge for up to one week.